I dont get it?! i think its the same sh!t?

ok if youv'e read my other Q"s you know i want a lip piercing ^_^ and a friend is doing it =] but here's my Question doest it really matter if a profesional or a friend /w Expierience pierce it? im asking b/c i had 2 friends one of them had done his own snake bited and eye brow piercing and my other friend went to go get the monro done profesionally done and hers [the monro one] got infected! and my guy friends [the guy] havent!! he has like 1 1/2 /w him and he ddnt himself so does it really matter who does it? i mean does in it really matter how you take care of it; cant ANY piercing get infected?