My younger brother and I used to be able to argue about anything. Every spoken word was an opportunity to show up each other. We had a burning desire to best each other, no matter how inocuous the task. "Oh, so you think you've seen more Three's Company episodes than me? So how high was the appartment building supposedly owned by the man whom Jack "saved" from choking in his restaurant?"
One of our favorite subjects for debate was music, and I remember arguing over who was born in the year which saw the best music released. It was 1971 vs 1973, and I am certain it turned violent. This may have saved us some bruises.