The one that defeats me (and I asked about this one here some time ago, but I'm damned if I can remember the answer!) is the saying that something 'sucks' meaning it's 'unpleasant', 'bad' or 'no good'.

Sucks what? And why?

I understand saying that something is 'shit', because that's likening it to an unpleasant substance, but 'sucks'....????

It don't make no sense, Guvnah! :-)