In addition to being turned down at résumé review for being too old, I just pulled an errant chest hair which seemed to be getting out of control, and it was as long as a Star Wars action figure. Many of its former neighbors are white hairs. I am definitely older than I feel, which I guess is a good thing. We hope to see so much proof though.
I think you will not be alone around here to go through that experience, given the ages of some of us. I have silver hair brushes around my temples now and just like you chest hair who I never paid mind too before has gotten denser, probably will have to roughly shave them infrequently. Mentally, it's not like a switch is instantly flipped in your head, you're still yourself and said yourself has been
young for all of its life at that point. Yet I myself am at the point you start to notice (or are being notified by society though job research, lodging research, etc...) you're slipping out of that gold 20-35 bracket where carelessness and instability is allowed if not expected and are now turning into a flaw.
TLDR : this place is gonna be hilarious ten years from now.