I also forget. Thankfully hair-washing is an idempotent operation for guys :) .

"Hygienic idempotency and creative reverie: Yet another male privilege?" is going to be my Gender Studies dissertation.

If you use shampoo, it's not idempotent. Over-shampooing hair dries out your scalp. A nontrivial number of guys with dandruff could benefit from shampooing less often.

I've been wondering about this. I have a bit of dandruff.

I really like the fluffy hair feeling i get when i wash most/all the grease out.

But sometimes i can wash my hair 4-5 times and it's still greasy!

Not if you have long hair like I do!

>Does anyone else forget if they washed their hair of not while having an epiphany?

I'm more likely to mindlessly apply body soap to my hair or shampoo to my body when solving problems in the shower. I'm always amused when my autopilot makes this mistake.