SPACE...please

Pet peeve alert! Why does the guy/gal behind me in line at the grocery store feel like they need to be an inch off my ass?  You are not getting to the clerk any sooner that close than you would be three inches farther back.  I think everyone in the world should get at least that much breathing room to call their own.  Tailgating is illegal when you drive and at the very least it's extremely frigging annoying in person.  Honestly, if I shift my purse and it hits you, you are WAY too close.  Oh, and while I'm at it, why can't you ask for the grocery space bar thingee instead of reaching past me to get it?  Rude!  It's no wonder people's kids are so ignorant when their parents can't show even the most basic respect.  When did we become such a nation of Grabby Gusses?  God!  Anyway, back to the space thing.  If the supermarket was the jungle (and sometimes it sure feels like it), you could get your face bitten off for being as close as some people get.  I've started keeping one foot way behind the other just so the butthead behind me can't push their cart any closer.  Relax, asshole, you're still next.  Just a thought....