What does it mean to be the best? You’re admired. You set the standard others try to achieve. You get the pick of opportunities. It sounds good—but is it? There’s a price to be paid for excellence. Being the best comes at a cost.

To become a doctor requires an extraordinary effort, starting for many in high school and lasting until they become M.D.s. The years in between are filled with long hours, rigorous preparation, and intense competition. Many candidates crack or decide the pressure is not worth it. Those who survive are entrusted with human lives. A handful rise to the top and are considered to be the best at what they do. Along the way, though, sacrifices must be made, and as Grey’s Anatomy has progressed from season one through the mid-point of season three, the audience has gained a greater understanding of what each of the interns and doctors has given up to get this far.

Cristina Yang and Preston Burke, as intern and head of cardiothoracic surgery, are at opposite ends of the arc from student to highly respected surgeon. And it is through their relationship that we have been able to best understand what each has had to sacrifice, and what those sacrifices have cost them.

When we first met Yang, she was driven, neither warm nor friendly. We recognized immediately that she has stuffed her humanity out of sight, ready to give up  …