This is a good habbit. Rats piss all over that shit in the storage units. I even found Dung on my cheeseWiz cap.

and you don't know what the shelf stacker has been doing with his hands.

You should use antibac, or bleach, as well. Actually, I wouldn't eat or drink anything from a store. You really don't know where it has been. And anything that has grown in the ground is pretty dirty. Also, animals are pretty dirty (just smell them) so don't eat them either.

Is this normal? No. Is it a good idea? Yeah, so continue to do it. When you start seeing the germs and they talk to you, then its time to go see shrink.

Bravo.

i's do that to but i'm to lazy

wiping off the top of a soda can is a good idea.
If the milk jug is dirty, then sure, wipe it off, otherwise I wouldn't bother. I never thought about the rat thing, but ya. If you're gonna cook your eggs, I wouldn't bother washing the eggs. They are actually washed before packaging.
Is this normal... no I wouldn't say that most people 'normally' do this, but it's not really a big deal. If it makes you feel better, then go for it.

A bit of grime never hurt anyone. The reason why allergies are on the rise is because we are too clean, the immune system gets bored/paranoid and starts to revolt at everyday normal stuff.

But if you want to wash your stuff then do it if it makes you happy :o)