Signs you might be older than you used to be:

Spontaneous, earnest, non-ironic utterance of  "when I was your age."  (Bonus level:  No one under 18 resides in your household.)  (Triple word score:  this having happened often enough that it's no longer cringe-inducing.)

Getting carded is a big, honking deal, brightening your whole week. 

Running out of sympathy cards.  (Bonus level:  using a coupon when you restock them.)

Feeling out-of-sorts when Collective Soul is played by the "classic rock" or "oldies" station.  (Bonus level:  knowing who originally coined the phrase.)  (Triple word score:  pronouncing her name correctly.)

Knowing what "TPMS" stands for, because the got-dang light has come on so many times.

A certain awareness of one's...fiber consumption.  (Bonus level:  discussion with a parental unit about theirs.)  (Triple word score: this having happened often enough that it's no longer cringe-inducing.) 

No longer having to Google how to plunge the toilet.  (Bonus level: Having to plunge is literally no sweat.)  (Triple word score:  You have achieved unclogging in ten seconds or less.)

Somebody else has commented on your fluency with medical terms.  (Bonus level:  Knowing which cholesterol is the good kind.)  (Triple word score:  Knowing which blood pressure number points to your level of chronic stress.)

Getting excited when a doctor hands you one of those cards that help pay for the new drug they've just prescribed.  (Bonus level:  You have enough of those cards to necessitate their own section in your coupon file.)  (Triple word score:  You know what your deductible is.) (Quintuple mega super word score: You know because somebody met it this year.) 

Gray hair that you treat with chemicals, or have a professional treat with chemicals.  (Bonus level: Gray hair ornery enough to require multiple chemical processes.)  (Triple word score:  You've quit it with the nasty, smelly chemicals, because there's just no point anymore.)