I've had years without a flat, and fractions of a second between them. If I have multiple flats on a four mile commute I'm going to apologize for being 5 minutes late if I'm on my way to work.

The weirdest one was getting a flat at one major intersection on the way to work, and getting another flat at the same intersection coming home from work. Different sides of a 6 lane divided highway. My then-wife said it was because I had killed a rat before going to work, and that was the rat's revenge. It's as good as any explanation I can think of.