It's no one thing for sure. Though it sounds strange, I never expected nor wanted to live past a set predetermined age that I had set. This age was somewhere right around 28. Oddly, I took some comfort in that and accepted it as my fait. I'm 31 now, and life kinda happened. Throughout my twenties, I went to college and obtained dual degrees in fields which interested me but that ultimately, I did not expect to work in. I seriously never planned for an adult future of any kind. Nearly four years ago, I became pregnant. I had a bit of a nervous breakdown about it for various reasons, but ultimately held it together. I got married while I was pregnant, and now have a husband, two step children (15 and 18), and an almost 3 year old! Basically, life crept up on me, but I'm still reeling! The responsibility is overwhelming! I'm just trying to keep up, but it's not easy trying to fashion a life when I didn't expect to be alive.