"Did you know that you are supposed to leave conditioner in for two minutes before rinsing??"
I looked up, surprised at the accusation in his voice.
"I did know. And I was keeping it from you. I'm sorry."
He rolled his eyes, and walked away.
After 30 years of using conditioner every day, this just blew his mind. Either his showers are a lot more exciting than mine are (and he never has time to read the bottles), or this is what happens when you never have sisters.
His showers are now 2 minutes longer.