Things that make you wonder why you only have 2 hands

You know when you've just finished loading up your hands with 35 grocery bags on one side and 23 on the other with an oddly shaped box under your armpit that is hanging on by the color of the letters on the side of it?

Please explain to me why in that EXACT moment, you nose decides to get a tiny little tickle that feels like the world will literally collapse on itself if you don't scratch it RIGHT NOW!!!!

I'm just asking.