Back around 1985 we had just made the jump from COBOL to C and were having a blast writing tools and games and toys. One I wrote just randomly toggled pixels on and off. I knew intuitively that while it started out blank, it would fill the screen then settle down and hover with around 50% coverage. I'm sure there is a mathmatical proof but "at a greater than 50% full the odds of hitting an ON pixel are greater than 50%" is all I can articulate.

Turns out this little program is multi-threaded! The more times you click the Go button the more processes run. And that is just fine.