I remember how pissed off I was after receiving my first contact from AARP. Still haven’t replied.
When the ladies in MILF porn still look too young for you.
When someone asks how old you are and you actually have to think about it before you can answer.
…or resort to grade school arithmetic…
When the ER doctor treating you for a burned foot says “You cannot have these readings without taking medication.”
SHIT!
I’m ever thankful to have been born on an even decade, makes the math phase of the conversation less awkward. 
That ought to help, for sure. But having been born in December makes my math complicated. I have to remember that it’s “not so fast, my friend” and then give back a number in the answer. Like, I won’t be 75 until December.
And being in the early part of the century doesn’t help much either. Carry a calculator, is the best hope.
When your all-time favorite band is mocked for being passé.
I just started saying “I’m in my early/mid/late (decade)”, makes it much easier. On the flip side, when I hang around with old friends we like to revert to childhood and say “I’m __ AND A HALF” when discussing age.
Whenever anyone asks me my age, I always quote Satchel Paige’s great line “How old would you be if you didn’t know how old you are?” Then I say “25, and I’m sticking to it.”
Or when the music you used to listened to when you fancied yourself a “Rebel”, becomes corporate mainstream.
Remember Punk?
when you look at the cop directing traffic and you wonder if his mama knows where he is.
This cracks me up, Lady!
You know you are old when you realize all your baby pictures are in black and white.
That, indeed (except that I’m not thinking of my parents who weren’t that young when I was born, but of other “adults” who were just “kids” by my current standards).
That also. Except that I began to think that the police (and the army) was recruiting in primary schools before I was 40.
I’m still not completely accustomed to the fact that they aren’t from WWI 
Daugerreotypes, to boot.
You know you’re getting old when you groan more from un-stiffening your body after sex than you did during it.
I didn’t read the entire thread but -------- when it started to take more time for me to pack my medications than it did my clothes.
Well, in this particular case, the reasons their mouths are open could be:
-
You are Abraham Zapruder, in which case this is really a zombie thread, since you died in 1970. Or
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You’re having delusions.
The Zapruder Filmwasn’t broadcast on television anywhere until 1970 (when it was played in Chicago and possibly elsewhere), and wasn’t shown on network TV until 1975.