1. Your 10-year high school reunion invite shows up in the mail.
10 years goes very fast, and it only gets faster.
2. You do your own taxes for the first time.
3. You pass on free concert tickets because the thought of being out past midnight on a weeknight doesn't sound as fun as it used to.
4. And if you do go out on a weeknight, you struggle through the entire next day.
5. One of your best friends has a kid.
A kid who attends the same preschool you attended.
6. You purchase the comfortable shoes instead of the stylish ones.
7. You have a year when all of your vacation time is used up going to friends' weddings.
8. You start using an email address with your real name for all of your correspondence.
9. You read the labels on food at the grocery store...
10. ...and get panicked instead of excited at the sight of candy.
11. You realize you like the taste of wine.
12. You watch a cooking show on TV.