My boss is younger than I am and is absolutely sure he knows more about my job than I do, even though I've been doing it since before he was born and he never did it at all.
People on TV keep trying to sell me stuff like Metamucil, some new kind of cane or similar silly gadget, or a scam investment, none of which I want.
My grandkids can't understand why I can't read things they're holding right in front of my face until I've spent twenty minutes finding, then cleaning, my glasses.
My wife has heard all of my jokes and all of my excuses. She now criticizes the former and laughs at the latter, instead of the other way around.
My friends sound like cranky old sticks-in-the-mud who wish they could turn back the clock to a time that wasn't nearly as wonderful as they claim to remember it was.
A trip to the supermarket now tires me out and instead of going out with (surviving) friends, I really look forward to taking a nap on the couch. Really.
The celebrities I recognize are senile and/or decrepit. The ones who are currently popular are appalling.
I don't have enough money to retire but dream of it every day (See the above comment about my boss).
Life is fantastic, except when it's not. Whichever it is now, pretty soon, it will be the other one.
My advice: Pay attention.