h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

When told to do something by my parents, I would naturally (being a curious/inquisitive/pain in the arse child) ask "why?".

I would invariably receive the answer "Because I said so"...

I have tried ever so hard to never say that to anyone, as I remember how frustrated I used to get at not receiving a "proper" reply, but have come to realise that it is used for a variety of reasons:

1) to buy more time to think of a better answer
2) because the answerer cannot be bothered to provide a better answer
3) because the answerer does not believe that you will understand a better answer
4) because they don't know either, and wish to retain an air of superiority despite that fact.

Just my twopenneth worth