I think thinking might be a good way for my case, since thinking has no dependency compared to other activities, I can think anywhere at any time. They are fun and play is essential in our lives (interestingly, the Greek word for recreational, fun activities is “psychagogia” (ψυχαγωγία) from psyche (soul/mind) and agoge (education/instruction)). Between the computer and all the outdoor activities I perform (walking, construction, and the first stages of farming my own stuff), I never find myself in a state of meaninglessness or boredom.