For nakedness, I suppose in being the 'charity guy' in my student union meant I had to manage the sports and societies naked calendar, meaning I had to go to the photoshoots, which was at times disturbing at times...well, at least considering the Rugby lads had theirs done on the pitch and we had a hard time controlling them because instead of lining up for their picture like everybody else, they decided to play Rugby in the view of everybody walking to university, even doing a line in (so touching each other's rear ends).
If anybody has no shame, it's rugby boys. Footballers and American footballers, even they had shame.
On the other hand, there were the cheerleaders.
But I'm not disrespectful nor am I perverted, so instead I'm just going to leave you with an image I couldn't avoid seeing to burn into your mind, in spirit of Insanity Complex's post.
[edit]
Even better. I posed naked for that calender, that's sure to scar some of you.
[edit2]
Re-reading the thread title, no, this
doesn't count as a childhood experience.