(On a non-mechanical escalator)
Lady (40): Excuse me, does this escalator go down?
Gustavo (39): It depends - if you're at the bottom it goes up...
Gustavo: Yes, yes, it goes down.
(Gustavo's comment: I must write one hundred times "I must not give stupid answers to people who don't know me. I must not....")
(Loosely translated from Blogudeces de la Vida Cotidiana, with thanks to Gustavo.)