I'm a very visual person. When someone tells me a story, I set up the scene in my head. What the room looks like, how many people are there, where people are standing, etc. If I actually visit the place in question later, I usually find out that I was dead wrong. But I still need my imaginary visual in place to be able to pay attention to the story.
Last year when Y was on his surgery rotation, he started telling me something funny someone said during a colonoscopy. As I started to create my fantasy-colonoscopy world (doesn't that sound fun? Sim Colonoscopy, anyone?), I realized I couldn't complete the scenario in my head: I wasn't sure exactly how one is positioned during a colonoscopy.
This was vital to my understanding of the story. So I interrupted Y and asked him.
Y has expressed interested in taking an academic career path; he's always liked to teach. So he did what any good teacher would do in this situation: demonstrated the proper position of a patient undergoing a colonoscopy:
That's the last time I ask him a medical question.