There is something called phimosis, which you could look up. My son is not circumcised, and it's been surprising to me how little his doctor knew about care of the penis in a young child, she even tried to pull up his foreskin which is a big no-no since there are connecting tissues that don't dissolve until later. Can't tell you if your circumcision was medically necessary or not, like if you had phimosis (but at age 3 no one's foreskin can be pulled back, so it seems unusual that they would know if it is improperly tight at 3). Overall, though, don't worry, some people are circumcised and others are not, it does not harm you to have been. I think the American Academy of Pediatrics finally released a recommendation recently to circumcise. If I recall it came down on that side of the issue because then the guy will not have as much of a chance to pass along HPV later, something like that. Please don't worry about it, as I said, some guys are and some guys aren't, and they are all normal.