"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". In actual conversation I'd suppress this because I suspect the other person will quickly find it extremely annoying. I just think to myself "I'll try to remember what he's saying and check it out later", but of course I don't have such a good memory."