I'm talking to somebody, and they mention something that reminds me of this joke about a rich man and a tourist, so I say "A dollar for the story of the rich man and the tourist" - the offer of a dollar is part of the joke, or a quote from somewhere.

I'm on the sidewalk in a city, and two people who are passing by instantly present tattered dollar bills. I laugh and take the three dollars (one from my friend), and I start to tell them the joke, but I have forgotten how it goes.