I never saw it coming, waiting for something for nothing

Facebook is blowing my mind. Ever since I reconnected with A. all of these ancient people from when I was barely older than N. have come out of the woodwork. I just received a friend request from a woman who I used to go to preschool with, our parents used to carpool. It has been almost 30 years since I last saw her. I had a crush on her all through grade school and high school, I used to walk her home from school all the time - and now look at us, we're middle aged, with our own children. It's actually sort of wonderful - and yet I think about all the things that have happened over the years, and am overcome with sadness and regret over the past.