why?

i went to town today (literally)

my friend and i were in the v&a museum and noticed a sign on a door saying:

lecture theatre
lifts
toilets

i noted this to be an almost perfect sentence.
i pointed out that the lecture theatre, not something usually associated with strength, has done well to lift the toilets.

he replied "why would they do that?"

not, "clearly it's not true," or "how is this possible", but "WHY?"

it doesn't seem so funny in writing does it? it was a lot funnier when we were there. i guess i'll have to get it reconstructed on the radio or something.