What was the straw that broke the camels back for you?

Awesome Question! I have many things... Firstly, I realized SOMETHING wasn't working right Summer 2006. I was on a 1500 calorie diet, working out EVERY DAY, teaching in the heat as a camp counselour and chugging water - and maybe lost 1 lb. In December 2006/Winter 2007, I noticed it was getting harder for me to run around, but I ignored it. By March, I would have to "break" on the stairs. Running up the subway stairs, I'd have to stop in the middle level to "check my metro card" or something. I would go out with my friends and they'd have to slow down from the shin splints - I'm a walker, people used to have trouble keeping up with me, even at my heavy weights! I was too tired to live right. And of course - the realization that at 22, I couldn't enjoy life properly.