In a supermarket
Old lady: And they rearrange the shelves all the time.
Guard: They do it on purpose. To see if you're awake.
Old lady: Well, I can never find anything.
Me: You know, it's to the supermarket's advantage to have you wandering around looking at the shelves.
Old lady: Well, it doesn't work with me. I just say (lowers voice) sod it, I'm leaving, I'll do without.
Me: And the world needs more people like you.
Guard: Yeah, everyone buys too much stuff, more than they need. And then they throw it away instead of giving it to the homeless.
I left them discussing practical socialism.