mini-moan: i am the arbitrator

Somebody said something to me the other day when I asked about the bangs (exclamation marks) they had written on a post-it note affixed to their monitor. I asked why they had used only 3 and not 5 and they replied.

Them - 'You can only use 1 or 3!'
Me - 'So you can't use 4?'
Them - 'No!!!'
Me - 'Or 2?'
Them - 'Certainly not!'
Me - 'Only 1 or 3?'
Me - 'Odd!!' (I only used 2 when I made that remark, but she didn't notice at the time).

As much as I enjoyed the conversation, why do humans feel the need to make these arbitrary rules? If I want 4 bangs I'm bloody well going to have them, although lately I'm lucky if I get a single bang!

It's Them against Me.