Studies in the field of neuroscience have shown that "will power" and probably "decision making" in general are illusions. When we become conscious of making a decision, the action potential has already occurred, which is to say, that the physical body acts first, then the mind becomes conscious of making a "decision". If we think of the mind in an integral sense, of transcending and including the physical body, this makes perfect sense. The significance of this though is quite profound, for it means that our decisions and actions are determined by dynamic behavioural patterns, which is really what the "I" of consciousness is.
We have all well-intended at one time or another that we are going to be productive on the weekend, maybe get some office work done, write a piece of music, or do some house maintenance; but it just doesn't get done. We sit down, read the newspaper for 15 mins, then talk to a friend, perhaps go for a walk, and so on, until the day has past. This is because when we think of the weekend, its an abstract object presented in our minds, and as mental abstraction, we never actually experience "the weekend"; what we do experience is one moment, then another moment, then another moment. It seems ridiculous to us after the fact that we didn't get anything done, I mean, we had the whole day.
If we do understand that decision is an illusion however, and that the "weekend" really is just a succession of moments, then it becomes apparent that in each moment that past, there was no behavioural directive to take such an action. Alternative actions, such as reading the newspaper, feel more comfortable, there was less tension, less resistance to such action. The corresponding cognitive impression, such as, "reading the paper is a small distraction, afterwards I will..." is of secondary concern, as its the conditioned behavioural patterning that determines action, yet of course we only concern ourselves with the cognitive phenomena.
There is a saying in zen monasteries, which is, "the schedule is your first teacher." Think about it, when are you the most productive, when do you follow through the most on your intentions? Invariably, after thinking on this question, you will conclude that it is precisely during times which are scheduled.
When we act based on a schedule, the action is unconscious, there is no tension in our awareness, nothing to feel better than the desired action. If I go to the gym at 6:30 am everyday, I won't think "should I go today", or "when should I go", I just grab my training gear and head out the door. Compare this to if I set an intention, "I will go to the gym tomorrow". At 6:30am the next morning I decide to have a cup of tea, I then think about when I should go to the gym, and this thought is now meeting conscious resistance, my apartment is warm, drinking the tea is relaxing and at this moment, I just don't feel like going to the gym. Maybe I decide that I really don't need to go today, maybe its better if I went to the office earlier, or relaxed a bit more, after all, I didn't sleep well last night, or whatever.
Now, I used the words "decide" quite a few times in this article, its really awkward to think of it differently, even when of course we know its an illusion, the fact is, this is how we evaluate our actions and fail to understand why we always fail in our intentions, why we can't get focused. With understanding that our "decisions" are dynamic behavioural patterns, we can clearly see that as we have not created a strong behavioural pattern to perform a given action, it thus doesn't occur.
Especially when these actions are up against well developed behavioural patterns of: sitting on the couch; drinking tea; reading the newspaper; checking Facebook etc. Its not that we are weak-willed, un-disciplined slackers; its that we have no will and are going with the flow. If you want to perform a given action, then there is no need for discipline or motivation, simply behaviourally condition yourself to do the action, without fail, at the exact same time everyday for a minimum of 21 days, it will then be nearly effortless.