1. The conversational equivalent to the phenomenon of coastline measurements* - getting so bogged down in the details of something that explaining it becomes impossible.
* The closer one looks at a coastline, the longer it gets.
2. Getting repeatedly lost/tangential while speaking and never completing a thought or idea. Often the result of being high.
1.
Cedric: It was last Tuesday; no I think Wednesday morning at 11:30, well, 11:40; no it was Tuesday because I was wearing my blue shirt-
Bored Colleague: Cedric, you're mapping the coast. Shut up or just tell me what happened.
2.
Dude 1: So, have you thought about what I said last night?
Dude 2: Yeah, you spent 3 hours mapping the coast and I nearly died of boredom. I'm not getting high with you again.