Lollipops

How come people will share a lollipop but not any other candy that's already been in their mouths? Taking a couple chews of used gum should be about the same as taking a lick of someone else's lollipop. Or do germs disappear if you wave them around on a stick?

My point is not, as one might believe, to point out that people shouldn't share lollipops. I just want to be able to chew used gum.