Harder times

There were two wheels in those old mice that used balls, one for up and down, one for left and right. They would gradually get covered with gunk until they couldn't turn anymore. The easiest way to clean them was with rubbing alcohol on a q-tip.

I know that but why would someone use a hardboiled Yolk as the ball

That part was just a joke, about the visual similarity between the two. Sorry about earlier, I thought you were asking about the wrong thing

It's aight my guy