I wore some sort of protection all the way through school and college because I had fairly regular wetting accidents ... not "floods", just quite regular small leaks. I am 58 now and have never been “reliably dry”.
I started school in the late sixties, when pull-ups and disposable diapers were not yet around. When I went to primary (elementary) school I wore plastic pants with an old cloth baby diapers. When I got a bit bigger the cloth diapers were folded in the crotch, rather than pinned onto me. I would have a spare diaper in my schoolbag, along with a waterproof bag to bring the wet one home if needed.
Later when I was a young teenager in secondary (high) school I wore PVC "Sandra Incontinence Pants" (I remember what it said on the boxes!) with a disposable insert pad. I can remember feeling the plastic sticking to my skin at the sides where there was no padding.
I don't remember anyone ever finding out ... or at least if they did, they didn't say anything. I’m glad about that because I would have been so embarrassed if other kids discovered my “terrible secret”.
Of course my parents knew, and every day when I got home from school my mom would always ask "Did you wet today? Did you change your pad? Do you need to put a new spare in your bag? Etc...", regardless of who else was around.
She didn't do it to embarrass me - both parents were very supportive of my problem - it was just a normal question to her, part of caring. But I was always SOOOO embarrassed if neighbors etc were there. Gradually when I was well into teenage years she got more discreet about it!
Anyway, thus started a fascination/fixation with plastic pants that never left me to this day. By the time I went to college disposable adult diapers were available (although they were TERRIBLE compared to what we have today!) so I wore those, but always with plastic pants on top.