Things I don't understand, Part 1

This is going to be a random, but possibly lengthy, series on things that confuse me somewhat.

It will contain questions about anything and everything.

Such as...

During the winter, when there is snow and ice on the ground and it doesn't get above zero, you see (some, not all) girls out in tiny skirts and the highest of heels.  As soon as the sun comes out, so do the long maxi dresses and flat sandals.  Why not the other way around?

Why does everyone in my street get their taxi to stop outside my house between 2am and 6am and not outside their own house?

Why do I have to learn about Islamic Finance?  I live in the UK, which as far as I am aware is not under Sharia Law.  If I was going to practise in an Islamic country I would study the rules then.

Why does the supermarket checkout line I join always move the slowest?

Part 2 will follow soon.