It taught me later on in life that mothers want their baby’s genitals to look like the genitals they’ve seen, and fathers want their babies genitals to look like theirs.

Initially I was told it was for religious and/or hygiene reasons, And while the religious reasons are still there in the religions the hygiene reasons are pretty much negated by taking a daily shower and having good personal hygiene.

I also learned later on that it was probably done initially to lessen the pleasure that you would get from masturbating. And if they could lessen the pleasure you get from it maybe you would do it less since the people at the time when it was put into regular practice thought that you touching yourself was the worst thing you could do.