Unsolved mysteries

There's one thing I will never understand about the British. I appreciate that's not an uncommon condition for an American to find himself in. But I've lived here most of my life; I went to school here. So I'm not ignorant, but still - I just don't get it.

The nearest thing I could liken it to is the British constitution. Like they say they've got one but when you ask them to produce it, turns out it's just a word of mouth thing. Doesn't really exist at all. They tell me the political system here is based on compromise; they have an "unwritten" constitution. No one can really say for sure what's in it, so they've agreed to stop arguing over it and have settled instead on arbitrary rule.

I prefer our text-based system myself but what can you say?

Oh, yeah, that thing I know I'll never understand: Mornington Crescent.

What's with that?