I have found that my attention slips from the tip of the minute hand toward the widest part of the minute hand. It doesn't move off to other things completely, but just enough to make sure I am 'not doing it'. I had the realization that this is a problem in other areas of life as well. It is the idea that something is 'good enough.' The problem is that 'good enough' means that you didn't actually do what you intended to do but are will to accept 'this other thing' in its place.
I have found that I invent games to try and keep my attention focused. A lot of the games are not even conscious, it is only after inspection that I even realize it was a game, and I wasn't doing it. The primary thing was I would find myself counting, maybe saying the number the second hand is on, or the just counting upwards.
Today was the first time I did the exercise for 10 minutes. I found I was actually more successful with the longer time. Having more time, let me grow as bored with the games I invented as with the original activity itself, so I was able to break through it, and just do it.