I don’t know about you, but I don't feel like an adult or at least my childhood vision of an "Adult” - not that I was ever aiming for that construct. 

Perhaps it has to do with my personality or informal view of myself. Or maybe it is because I don't have the responsibility of children; when you have kids I’d imagine you have a greater sense of time passing through witnessing their growth and evolution.  Also, if you’re a parent people call you Mister or Missus; I have rarely ever been introduced as Mr. Sale so perhaps that has contributed to thwarting a more formal-vision of myself from taking root.

I definitely recognize an Adult when I see one, and I see them all around me – I even see Adults who are much younger than me.  Yet even if we’re the same age, I somehow don’t feel like their peer or colleague.  I don’t even feel like I look like an Adult, of course I have pretty lousy vision...so for sure I definitely have Adult eyeballs, possibly even Grandpa peepers.  Maybe I am an Adult but don't know it.  Maybe it's my brain's way protecting me with that wonderful drug, denial. FYI - I'm 48 yo.