Old?

I'll be turning 31 this week & it's not just yet time for me to buy some life insurance for senior, but there are moments, when I wonder when I got old. Like seeing kids that I used to teach at the daycare & they are now driving. Or kids that were in the youth group, when I was a youth leader & they are now married & having babies. It's also weird seeing trends that were popular when I was growing up, making comebacks.