Skill: Compartmentalizing, or keeping track of threads and subthreads in a discussion so that it doesn’t become derailed by minutiae.
This is more important in board meetings with Robert’s Rules of Order in place, but it can be useful in general rational discussion. Just last night I my friend was helping me with C++ references and we got caught up over array pointers, forgetting entirely about the bug we were trying to solve.
Exercise: keep a physical stack trace on a whiteboard or something when talking
As topics become reframed for clarity, you can resolve child topics if they become irrelevant.