All modern mouses have inbuilt click counters for both the left and right mouse buttons. It is the easter egg of computer hardware, and has surprisingly enough gone by largely undiscovered. I didn't believe it when I first heard about it, but the other day I trashed some mouses and decided to open them and see just in case. And lo and behold, I saw that they actually do have click counters, seemingly regardless of brand at that. Both my counters were grey little boxes on the inside rims of the opened mouses, but they may look a bit different for you, depending on brand.
If you don't believe me, get a screwdriver and check for yourself. It will take you 2 minutes.
