Fat men are the only ones to wear goatees or that all fat men have them. I bet most are the result of laziness. If you go a long weekend without shaving and are looking in the mirror ready to shave I think a lot of guys will experiment. See what the Fu-Manchu looks like, Check out that porn star mustache, try out the goatee. Then if they think it looks good they leave it and get a lot of comments on it like a fat chick with an over sized gaudy necklace. A few positive comments are enough to keep if for years.
I think the 70's porn star mustache is the next to come back.

BTW: Can you grow a goatee?
