Lately I've been thinking about the importance of mental focus, and how it relates to the principle of being "in the moment" (meaning the present, not thinking about the past or future). My mind likes to wander and think about other things rather than what I'm actually doing, and there are certain activities that make this obvious. When I play Dance Dance Revolution, obviously I have to give my full attention to the step patterns, how to shift my weight, and so on, and after years of practice I can generally get through anything the game can throw at me. But if my mind wanders to thinking about what I'm going to have for breakfast (for example), I will definitely miss a step. It's amazing, since DDR becomes a kind of instant feedback - I know immediately when my mind is focused on the present moment and when it's not! This also happens with simple things like flossing. When my brain wanders off I can't remember if I have done the bottom or top teeth yet, so I have to do them again!
On the other hand, when I'm taking a walk I love to think about other things. Sometimes I try "walking meditation" (where I only focus on the walk and try to empty my mind), but usually when I walk my mind opens up and suddenly remembers all kinds of things and gets lots of great ideas (this happens in the shower, too)! In this case, the challenge is to remember these thoughts until the walk is over and I can write them down! I usually have to come up with a silly mnemonic so I don't forget. In general, I truly cherish the luxury of mental focus, which is one of the reasons I love my alone time where I can shut out all external influences if I want. Giving my mind room to breathe helps keep me sane and relaxed!