I'm usually on my bike for 6-9 hours a day. A lot of people ask me how I keep myself from getting bored. I do get bored. I can't listen to music because I have to listen for cars. I can't draw while I ride (yet). I get very bored.
Usually, I talk to myself, either out loud or in my head. Once in a while, I sing. I make up stupid little songs about roadkill or girls in Brooklyn or food. Sometimes, I run out of things to talk about. I zone out. I try to erase my mind. Trying think about nothing is really hard. Inevitably, that chore gives me something something to mull over. It's can be a vicious cycle.
I'm thinking of getting a harmonica.