Go over to Sean Widmer.com... he has a great podcast where he talks about signs of getting old. I can completely relate since the following is happening...
1. Go to the bar, or stay home and watch The Big Bang Theory and How I Met Your Mother. Barney wins.
2. I keep it under the speed limit because there's no way I'm dishing out money for a speeding ticket.
3. When I go to the mall, I spend the entire time thinking "all these f-ing high schoolers look like a bunch of wannabe vampires and Lady GaGa knock-offs. What the hell is wrong with them? Damn kids!"
4. Two beers gets me drunk.
5. I saw an ad for "a healthy liver pill" that would "give you more energy" and thought to myself "hmmm, I should probably go for that"
6. I'm starting a retirement fund.
Awesome. I'm now old.