Hummmm, that is a good question. Seems to me that if you are losing track of the amount of time it takes to do a job, that perhaps in order to do that job you are all totally focused on it. It may be that you are having some trouble with focus and concentration and that the committment to the task is not allowing for typical time management type awareness? This is a total guess of course. It is an interesting question really.
I don't have an answers. Keep us posted. Now that you are aware of the problem, it will be interesting to see if that changes things.