This is like looking down a telescope the wrong end... Because I'm a certain age, when I'm with Susie, my 10 year old daughter, people often start a conversation with her, in shops, at the till, sometimes at the kiosk waiting to pay to get in somewhere, and I'll hear, "... and what about Grandad? Is Grandad looking after you today"? To which Susie nonchalantly responds, "well, that's my Daddy!" (Cue mild mortification of person.!)
So if it's at an entry point, said person, apologising profusely, adjust the fare UP to an Adult. To which I have to tell them, "Well, sorry, but I'm actually 73..." (Cue more spluttering apologies as they adjust it back down.)
Happens a lot.
Makes me smile.