For some reason, this is a very funny thing to say when you and your friends are on acid, and logic slips vaguely back into place for a moment. This isn't a playground thing, it's just something I wanted to share. If it encourages children to take acid, all the better. Anybody got any spare acid?

What isn't so funny is the somewhat smarmy reply of "Keep shovelling, Watson" which tends to bring things back down to Earth with a bump.

This was more of a playground and less of an acid thing for us (mores he pity) - used when some spaz states the blindingly obvious. Actually lead rise to one fat kid, David Lucas, being called Sherlock (Also had a lot to do with his girly 1930's coat). If you said it to him though, he would gob on you, forcing you to beat the shit out of him.
What was really nice is that I gave him a temp job while I was working in recruitment, packing sausages for minimum wage - and put the name on the pay slip as David Sherlock Lucas. OK, not hilarious, but it chuffed me no end.