[wfvr]

I believe that my bathroom and everything in it is full of germs; I also believe that my body has been perfectly able to deal with those germs for the last 40 years, as I don't really get sick besides the yearly-or-so cold or flu.

Taking my toothbrush out of the bathroom for the fist time at this point in my life because of "the germs" would be paranoid behaviour, in my opinion. It's not that there aren't germs, it's that they've always been there and I'm still here and healthy.

[burnished]

I don't really understand what you are getting at. Why is it relevant that you don't feel concerned about spaces contaminated by the germs you personally brought? Of course you don't.

I also don't understand what your toothbrush has to do with this. Please try considering this from the perspective of establishing practice for a bathroom shared by more than one individual: its probably important to know if closing the lid is an effective hygiene technique or not.