You may get hurt

Things idiots say to....people with children when they themselves have none.

"I babysit my (niece/nephew/friend's child) all the time.  Being a parent is sooo easy.  Why do people say it's hard?"

I have news for you, I don't care if you are the best super nanny in the world and have your own tv show where you tell people they are crap parents and you get paid for it.  Parenting is hard work.  Kids are almost always more well behaved for other people when not with their parents.  Why?  1.  You aren't their parent a.k.a. the authority figure.  No offense, but really are you going to ground them or take away their xbox?  2.  They've usually been warned within an inch of their life to behave for you.  Until you are in charge of that child 24/7, 365 days a year, you don't get it.  And you won't get it until you are a parent.  And yes, every single time you try and tell us all about parenting, we smile at your face and roll our eyes behind your back.   YOU.DON'T.GET.IT.