Grey's Anatomy: The evolution of Meredith Grey

Season 1

Best line: "Remember when you were a kid and your biggest worry was, like, if you'd get a bike for your birthday or if you'd get to eat cookies for breakfast. Being an adult? Totally overrated. I mean seriously, don't be fooled by all the hot shoes and the great sex and the no parents anywhere telling you what to do. Adulthood is responsibility."

Relationship status: A one-night stand with Dr. Derek Shepherd (Patrick Dempsey) turns into a secret relationship turns into a public relationship. Meredith's (Ellen Pompeo) future with Derek comes into question with the surprise arrival of Derek's estranged wife, Dr. Addison Montgomery-Shepherd (Kate Walsh).

Most important developments: Meredith becomes best friends with Cristina Yang (Sandra Oh) despite their shared hatred for showing emotion, makes it through her first run of residency, moves in with George O'Malley (T.R. Knight) and Izzie Stevens (Katherine Heigl), and deals with her mother's Alzheimer's diagnosis.

Season 2

Best line: "Okay, here it is. Your choice, it's simple, her or me. And I'm sure she's really great. But Derek, I love you. In a really really big pretend to like your taste in music, let you eat the last piece of cheesecake, hold a radio over my head outside your window, unfortunate way that makes me hate you...love you. So pick me. Choose me. Love me."

Relationship status: Meredith and Derek continue to date with the added awkwardness of Addison's presence. As Derek and Addison take steps toward divorcing, Meredith comes forward with her feelings for Derek only for them to go unanswered. She spends time with various suitors—including one terrible night with George—before juggling dates with Derek and veterinarian Finn Dandridge (Chris O'Donnell), and closes out the season with a mid-hospital prom, secret tryst with Derek.

Most important developments: Meredith faces Derek's past with Addison, continues to care for her ailing mother, and pieces together Ellis' (Kate Burton) adulterous relationship with Chief Richard Webber (James Pickens Jr.). She supports Cristina through the loss of a pregnancy, confronts her father Thatcher Grey (Jeff Perry), and gets involved in Izzie's questionable medical care of Denny Duquette (Jeffrey Dean Morgan).

Season 3

Best line: "Time flies. Time waits for no man. Time heals all wounds. All any of us wants is more time. Time to stand up. Time to grow up. Time to let go. Time."

Relationship status: Meredith struggles to choose between Derek and Finn, but finally breaks things off with the vet. After some time apart, she starts things up with Derek again.

Most important developments: Meredith gets her appendix removed, reunites with Derek, continues to get pulled in to encounters with her father's second family, and deals with her mother's disappointment. Her rocky period comes to a head when she nearly dies after drowning and is pulled out of the water by Derek, during which time she has contact with the dead and learns about the death of her mother. She then loses her stepmother, retakes her intern exam, and runs into trouble with her father.

Season 4

Best line: "Change; we don't like it, we fear it, but we can't stop it from coming. We either adapt to change or we get left behind. And it hurts to grow, anybody who tells you it doesn't is lying. But here's the truth: The more things change, the more they stay the same. And sometimes, oh, sometimes change is good. Oh, sometimes, change is...everything."

Relationship status: Meredith and Derek are both ready to commit and get serious, but not at the same time. They part ways, leading to Derek's short-lived relationship with the nurse Rose (Lauren Stamile). The two spend more time together inside the hospital walls, resulting in a romantic reconciliation.

Most important developments: Meredith gets her own interns after passing the intern exam, reluctantly works on her relationship with her sister Lexie Grey (Chyler Leigh), and starts a clinical trial for tumor patients with Derek by her side.

Season 5

Best line: "We enter the world alone, and we leave it alone. And everything that happens in between, we owe it to ourselves to find a little company. We need help. We need support. Otherwise, we're in it by ourselves. Strangers. Cut off from each other. And we forget just how connected we all are. So instead, we choose love. We choose life. And for a moment, we feel just a little bit less alone."

Relationship status: Meredith commits to Derek, letting him into her life so much that he decides to propose. Nodding to their romantic beginnings, Derek asks Meredith to marry him in a hospital elevator, covering the walls with mementos from their time together. She and Derek finally tie the knot by writing their vows on a Post-it.

Most important developments: Meredith learns that Izzie has cancer, gets engaged to Derek after he performs surgery on Izzie, does her first solo surgery, reunites with her trouble-making friend Sadie Harris (Melissa George), and goes through growing pains in her friendship with Cristina. She plans her wedding to Derek in a way that will make Izzie happy, only to hand the day over for Izzie and Alex Karev (Justin Chambers) to walk down the aisle. In the finale, she fails to save a patient whom she thinks is George.

Season 6

Best line: "Ask most people what they want out of life and the answer is simple: to be happy. Maybe it's this expectation, though, of wanting to be happy that just keeps us from ever getting there. Maybe the more we try to will ourselves to states of bliss, the more confused we get—to the point where we don't recognize ourselves. Instead, we just keep smiling—trying to be the happy people we wish we were. Until it eventually hits us, it's been there all along. Not in our dreams or our hopes, but in the known, the comfortable, the familiar."

Relationship status: Meredith and Derek are lovesick newlyweds, but the honeymoon period wears off when Derek becomes Chief of Surgery. They handle Derek's new responsibilities and begin to discuss having children.

Most important developments: Meredith deals with the death of George, goes through her hospital's merger, reluctantly agrees to donate part of her liver to her father, and gets pregnant. She loses the pregnancy in the midst of dealing with a gunman in the hospital.

Season 7

Best line: "People are really romantic about the beginnings of things. Fresh start, clean slate, a world of possibility. But no matter what new adventure you're embarking on, you're still you. You bring you into every new beginning in your life. So how different can it possibly be? It's all everybody wants, right? Clean slate, a new beginning. Like that's gonna be any easier. Ask the guy pushing the boulder up the hill. Nothing is easy about starting over. Nothing at all."

Relationship status: Meredith and Derek work through the emotional effects of the shooting, and evaluate different options for starting a family. Derek starts a clinical trial to treat Alzheimer's, inspired largely by Meredith carrying a gene for the disease. Their relationship turns sour when it comes out that she has tampered with the trial in an attempt to give the right drugs to Adele Webber (Loretta Devine).

Most important developments: Meredith recovers from her miscarriage and works toward getting cleared for surgery after the shooting, learns that it may be hard for her to have children but takes steps toward adopting a baby with Derek, watches Cristina marry Owen Hunt (Kevin McKidd), and gets caught up in the drama surrounding the clinical trial.

Season 8

Best line: "Carpe diem. How annoying is carpe diem? How are you supposed to plan a life? A career? A family? If you're always carpe-ing the diem? If we all seized every moment of every day, there wouldn't be doctors. Who would sit through med school? We'd all be too busy, living in the now. Whatever that means."

Relationship status: On rocky terms after the trial tampering and Meredith's decision to flee with Zola, she and Derek work on their relationship, becoming a strong parenting team for baby Zola.

Most important developments: Meredith faces heat for her questionable involvement with the Alzheimer's trial and fights to get Zola back, continues her career in general medicine, and winds up in a scary situation with Alex after the ambulance they're in gets into an accident. She passes her boards, evaluates what her life could've been like in an alternate reality "If/Then" episode, and finds a terrifying new reality when she gets into a plane crash alongside Derek, Lexie, Cristina, Dr. Arizona Robbins (Jessica Capshaw), and Dr. Mark Sloan (Eric Dane).

Season 9

Best line: "They say death is hardest on the living. It's tough to actually say goodbye. Sometimes it's impossible. You never really stop feeling the loss. It's what makes things so bittersweet. We leave little bits of ourselves behind, little reminders, a lifetime of memories, photos, trinkets, things to remember us by...even when we're gone."

Relationship status: As they continue to heal physically and emotionally from the plane crash, Meredith and Derek raise their daughter Zola and look toward the future as Meredith gets pregnant. They welcome a son and name the baby after Bailey (Chandra Wilson).

Most important developments: Meredith copes with the deaths of Mark and Lexie, and is forced to continue to relive the plane crash as insurance settlements are made. She fights to get Cristina back to Seattle and the hospital, serves as a bridesmaid in Bailey's wedding, works with her co-workers to save the hospital, and gives birth to a baby boy.

Season 10

Best line: "Failure is inevitable. Unavoidable. But failure should never get the last word. You have to hold on to what you want. You have to not take 'no' for an answer, and take what's coming to you. Never give in. Never give up. Stand up. Stand up, and take it."

Relationship status: Derek reaches new heights in his career as he works on a project with the White House, but is consequently pulled away from Seattle and his family. Meredith and Derek try to find a balance between their careers and parenting, butting heads at times over the workload, but continuing to love and support one another.

Most important developments: Meredith says goodbye to her best friend Cristina, cares for Dr. Webber as his next of kin, explores new techniques by working with a 3-D printer, and evaluates the next steps in her career.

Season 11

Best line: "I can live without you, but I don't want to. I don't ever want to."

Relationship status: Derek and Meredith continue to try to find a balance in their careers and family, coming to a head as Derek decides to quit his work in Washington, D.C. and return home to his wife and children in Seattle for good. As Derek heads out for his final trip to the East Coast, he gets into a tragic car crash that leads to his eventual death, widowing Meredith.

Most important developments: Meredith meets Maggie Pierce (Kelly J. McCreary), the half-sister she never knew she had, becomes close with Derek's sister Amelia Shepherd (Caterina Scorsone), and makes the decision to take a brain-dead Derek off of life support after the accident. She flees Seattle with her two children, and welcomes a third child, with whom she became pregnant before Derek's death.

Season 12

What's next: After months of dodging his calls, Meredith finally speaks to Alex and moves back to Seattle along with her three children. She is now raising the kids as a single mother, and is taking the first steps to getting back into the O.R., leaning on Alex and her sister Maggie as she gets back on her feet.

"Doing a show this long, the challenge is to make every year fresh and new, and to give it a different feel to keep the audience engaged," actress Ellen Pompeo told EW in an interview. "Everyone can agree [season 11] was pretty dark tonally. We were telling volatile stories, and [season 12]...has a lighter look. It's brighter. We [tried] to go back a little bit more to the original Grey's and have a little bit of a lighter tone."