This week on Thinking Thursday I asked you to come up with the answer to Lewis Carroll’s famous riddle:

Why is a raven like a writing desk?

Yes, it is a bit of a trick question because Carroll never intended there to be an answer; it was all part of Alice asking a serious question about the, to a child, mindless pursuits of adults.
However eventually Carroll did provide an answer:

Because it can produce a few notes, tho they are very flat; and it is nevar put with the wrong end in front!

The spelling of “nevar” is Carroll’s original, being “raven” backwards, but was lost in the printed version due to an over-zealous proofreader.
Of course this hasn’t stopped many other people providing clever answers, including “because Poe wrote on both” and “because they both come with inky quills”. You can find a longer explanation at, inter alia, wiseGEEK.
But I think the answer I like best is “because neither one is made of cheese“. Nor is either a helium balloon.