Cleaning Balls again

Maybe its just me, but I think I do have a problem. Everytime I use a mouse which is not mine, I always have to start looking at its bottom. For example, this morning, while I was using one, I noticed that whenever I press the left mouse button, the mouse tends to 'sink' to the left. And then, when I press the right mouse button, it did the same too.

Maybe ite because the mouse fell down to the floor a few times which I suspect, the cover dislodged itself. But in reality, it was not the case. There was a very large flattened dust/grime/dirt ball underneath. And it would not come off easily which meant I have to use my fingernail scrape it off..........

Imagine all the dead cells from skins and sweat on the
surface of past users all accumulated into this little
flattened ball. Needed to wash my hands a few times