I don't need to know Algebra

Things my dad tought me that I've used recently in circumstances in which I would not have chosen to find myself.

1. When walking on the sidewalk with someone else, walk on the streetside.
2. Not making a decision is the same as making the opposite of that decision.

paraphrased, of course. I'd have him confirm, but he's, you know, dead.

Maybe something else will pop up that I'll remember, but I think those are the two main things I can remember learning that I can put into simple sentences.