nah.
you should be willing to share experiences. They are who you are. And that 'embarrassing story' is a lesson learned. Especially if you consider failing to be as fun as success.
Buuut, Lets not go overboard. I wouldnt tell people about truly embarrassing things.
To answer about exhibitionism:
I guess its always been a desire. I was on the football team in high school not because I liked the sport (though I do), but because of the social exposure it got me. I mooned the volleyball team because of the exposure (and they lost). In college I was dating a girl who encouraged it and so I was streaking in the snow for fun and I even ran around the dorm naked.
I would pose for pictures because of the exposure. It was always about the money, but the casual thrill is worth its weight. To be specimen to be admired? ohyes. To be hit on by both sexes, to know that in addition you were scary enough to be relatively safe from attack, to be alpha by just being present. To be high on life, and consider yourself intelligent enough to mingle well?
But, secrets should not* be kept because they are embarrassing. And since the least amount of dissonance with oneself means the greatest happiness, these small things are not something to hide. They make fun stories, and they speak volumes about you. Being able to laugh at yourself is important. Being able to tell an interesting story is important. Being able to have fun with your own guilt and shame is admirable.
:| Dont know, Im sure theres many things going into that.
The secrets you keep should be those you dont want to share, not because they will make others laugh at you but more because they are special. Lifes too short and too many people are walking around to be over-concerned with any scorn from one group.