You know you're in over your head when you're just doing a little background research and find review papers with titles like "Matrix metalloproteinases: What do they not do?"
Okay, it's not quite champagne time, but I just sent the last piece of a complete first draft of my thesis to my advisor!
Still a lot of work to do, but now it's all editing and clean up (unless my advisor asks for any additions or expansions, which I don't think she will).
ETA: Apparently it's champagne time, after all. Maritus bought a bottle while he was out shopping for dinner.
That moment when you finish something you've been working on for a long time, and you're filled with a sense of accomplishment, and then you look up and take in your surroundings and think "This house is a mess."