1. You just generally give less of a shit.
2. 11 p.m. has become a socially acceptable bedtime.
3. When you're around younger people, you can still claim "being in your twenties," but you can also hang around thirtysomethings with ease.
4. Craft beer is delicious.
5. You can look back on your twentysomething heartbreaks as learning experiences, and not just soul-crushing acts of emotional sadism.
6. Gossip bothers you WAY less now.
7. You've made the extremely wise decision of investing in a memory-foam pillow.
8. You don't feel the need to join every single new social media network.
9. All your friends are just as tired as you are.
10. You have no problem telling people to go jump in a lake.
11. No one will judge you for ordering white wine at a bar.
12. You don't have to care about knowing what an "Avicii" is.
13. You're old enough to remember Friends.
(source)