
I went through that too (disabled at 34).
Fortunately the "elderly" of the future understand this a bit better. The elderly of "my" day and still some very elderly today just never, or rarely, saw a young disabled person (who could drive.) It isn't their personality, it's their lack of experience perhaps? Also, most very elderly only associate with others of their age and don't realize how dangerous the world is.
(I think also those who are in 80s+ had a mindset to work through your pain and don't complain. Of course there are those who complain about everything anyway.)
But in this vein, I was just parking lot "ticketed" for where I parked.

I tried to speak with the non-English speaking security about their mistake but alas it did no good. Fortunately I let it roll that he refused to be educated. I won't be towed the next time I park in the same place anyway. They don't tow handicap vehicles here. Plus, I had already educated the management--complete with MY calling the police--years ago.
Let it go if you can. I know for myself the reason it hurt was because it was true...at my age I SHOULD NOT HAVE HAD to be disabled...but then, who does???
I just smile at them and nod now...drives them nutso! If they come up to me close enough to say something, I tell them thank you for looking out for the handicapped and how WE can't have nonhandicapped people parking in our places. lol