I think I know what killed my old mouse: cat hair. I noticed that the new mouse (actually a spare I pulled out of a drawer) is skidding a bit. It’s hard to avoid cat hair everywhere when the cats like to sit on my lap as I’m working at the computer.
I picked up a can of compressed air and gave everything a good blow. I got quite a bit out of the keyboard. Say, anybody have some good suggestions for cleaning the surface of a keyboard spotted with … mmm I have no idea? Probably coffee, food, assorted detritus of life?