I was mainly talking about conversations like the ones described in Kaj's post, where the participants are just "making conversation" and do not have any specific goals in mind.

Always have a goal. "Just making conversation" doesn't count. That's a high-level description of the activity that leaves out the goal, not a description of something that actually has no goal. Your goal might be "learn from this person", "let this person learn from me", "get to know this person", "get an introduction to this person's friends", "get into bed with this person", or many other things, or even at the meta-level, "find out if this is an interesting person to know". Unless your efforts are about something, the whole activity will seem pointless, because it is.

I typically find myself wanting to verify every single fact or idea that I hadn't heard of before, and say either "hold on, I need to think about that for a few minutes" or "let me check that on Google/Wikipedia".

Have you ever been in a conversation with someone who had the same urge?