A lot of people worry that the youngs will grow up with an idea that all genitals look the same: because, porn. Well they don’t, as you can see in these drawings (by the most excellent Stuart F. Taylor).
Although there is no bone in the human penis (I’m only doing Sex Ed for humans here I’m afraid) you can break your penis.
Lots of people struggle with having a small dick. It’s not a surprise, because we all taught that dick size is very important – particularly if you’re a man.