Oh, I'm always taking notes whether work or business. I have notes that go back to 2005 on my home computer dealing with rental payments, college transcripts, gas payments and bills when calling up 1800 numbers for support, etc. It isn't that I don't trust my memory, it is just that if I am being pressured to do something it is a lot easier when I can look at the outcome/promise from the previous conversation.
That's what I meant! Having a written conversation about X means the notes are all already there for you. I've worked with so many people, both colleagues and clients, who use phone calls / in-person meetings as a way to essentially pass the buck while hiding any evidence that that happened. An auditable paper trail is preferable to me in every way.