I, too, went to an all boys grammar. We had an outdoor pool in which we swam every day of the summer term. Naked. The water was so cold sometimes that we did not swim for long but it was said to be character forming. Everyone's genitalia shrank to a small size owing to the cold water.
This activity stopped after I had left .
I have , as aresult, never had inhibitions about public nudity
...gym master asked who was in the swimming teams of their primary schools. I put my hand up along with 2 other boys. Then he asked who was swimming team captains at primary school.Only I put my hand up. He told me to go and hang my towel up on peg number 1 at thedeep end of the pool. I did so,turned around and stood there naked aloneon the side of the pool. I felt very embarrassed andvenerable as everyone juststared at my naked body, and were whispering to each other. I wanted to try and cover my nudity with my hands. The gym master blew his whistle for silence. Then he told the other 2 boys to join me. He then asked any boys who could not swim to put their hands up and go to the shallow end of the pool and hang their towel up on the pegs. The remainder of the boys joined me...
Aside from this being a really hot story-starter...
In all seriousness, congratulations for losing inhibitions! You were self conscious, so were the other students, and those who weren't we're showed-up by your abilities as an athlete!
Pretty much the perfect scenario for self-esteem building, if I don't say.
(Oh yeah, looking down every now and then should help keep your self confidence 'up', too!)