I noticed that I often hold conversations in my head while biking. It's quite strange: I start cycling a route I know by heart (work commute, for example), and after a few minutes, the conversations start. Last week I avoided a discussion with another person because I knew my argumentation had a serious flaw, and I couldn't find a way to argue around it. After biking to the supermarket on Saturday and holding that exact conversation in my head, I suddenly had it.