1. When the crap on the floor after your haircut is half grey.
2. The hangover lasts for 3 days instead of 3 hours.
3. There's just a few tufts & stray hairs instead of crap all over the floor for the hairdresser to sweep up after your haircut.
4. Sound bites from annoyingly conservative politicians sometimes sound quite reasonable.
5. You dig out that awesome EBM/darkwave album from 1994 and it sounds like noisy shite.
6. You find yourself spending as much time in your trakkie daks as your jeans.
7. Wrinkles appear on parts of the body other than the face.
8. Chasing a pizza and a DVD on a Friday night sounds like a much, much better idea than chasing Es and tail at Club Latest Fad.
9. That routine medical check comes back positive for something or other.
10. You see teenagers walking down the the street and the sight of them really, really irritates you for no particular reason.
11. Ads for funeral insurance pique your interest.
12. You start to wonder if maybe violent video games and pornography might be not such harmless phenomena after all.
13. Songs you grew up with are getting played not just on FM classic radio, but also on AM classic radio.
14. All your friends on Facebook have spouses and/or kids, except for you.