I like your "wet paint" analogy. That's very true - the human mind is a curious one. But also there's this thing called "instinct" and it doesn't have an off switch. When I pick up a loaf of bread I squeeze it to see if it feels fresh. When I buy eggs I pick up the box and open it to see if any of them are already on the way to becoming an omelette, and if so, I put it back. When I go to buy clothes I touch them to see what the fabric feels like. When I buy tins of beer (something I rarely used to do before lockdown) I pick up the tin to try and read the tiny writing to see what strength it is. I know I shouldn't be doing any of these things, but I can't help it! And neither can the majority of folks.
I was in Tesco Archer road a few weeks ago, I got to the checkout and realised I'd done my usual trick, forgot to bring a bag in with me. I'd got a load of them in my car boot but no way was I going to go back out to the car and queue to come back in again! So I saw these bags hanging on the end of the checkout and thought, "sod it, I'll have to buy one". I picked up this bag, then realised it wasn't a normal carrier bag, it was one of those with little partitions in it for carrying bottles, so I put it back. I heard this voice behind me say, "I wish folks wouldn't pick things up if they don't intend buying 'em".
I restrained myself from reacting, although it did cross my mind. I could have turned round and explained that it wasn't clear what type of bags these were, I could have said, I thought I wanted one but now I don't. I could have explained that even if that bag had been touched by someone with Covid-19 the chances of anyone catching it from touching it are practically zero. Because if the government and their advisors can't explain that to the general public then I think I'd probably struggle as well. So, I just sucked it up and bought a proper carrier bag when I got to the other end of the checkout, knowing that that bag had been touched by dozens of folks before me.
I just love living life on the edge!