Allrighty then...
In between the decision to do a thing, the formation of the "I will..." statement, a large number of things took place that may or may not have been related to the actual execution of the "will". Most of those things required no conscious thought whatsoever, you just did them. Most of them had the potential to divert you from the "will", or had the potential to fail, thereby preventing completion of the "will" and setting you on a completely different course. "I will..." is nothing more than the expression of a strongly held hope for the future.
Take for example, "I will have a cup of tea." Skipping straight to where you're sitting down with a fresh, steaming cup of tea on the table in front of you... You momentarily think about the weather. Next thing you know there's a cup of your tea in your hand and hot liquid going down your throat. At no time did you think "I will reach out, I will take hold of the cup, carefully adjusting pressure and balance to ensure that I don't drop the cup or spill the liquid, I will slightly open my mouth, I will test the temperature of the tea, I will tillt the cup and allow fluid to enter my mouth, I will swallow, I will go 'aaah'.
All of that was accomplished by your trained subconscious. You might at this point savour the flavour in your mouth and be consciously aware that you successfully swallowed a mouthful of tea. Your conscious may congratulate you on a job well done.
In an ordinary day we go from doing one thing to another with almost no thought whatsoever. We may have some vague "I will..." lurking somewhere, something like, "I will do my day's work and come home." but everything in between is largely a mindless blur, interspersed with brief periods of concentration on a specific task.
Moving on to the next level at which our conscious is oblivious to our activity, we have the matter of small scale timing. Everything we know about our environment is historic data. The most recent real-time data we have is about the state of the tip of our nose, being that it has the shortest light path to our eyes, which are our fastest sense, being most closely integrated to the brain. The light from the tip of our nose takes a few nanoseconds to reach our retina. Everything else takes much longer. Sense of touch and hearing are downright slow, given sound and nerve-electrical impulses are much slower than light. Bear in mind that a few nanoseconds is sufficient for the average computer to perform at least one operation.
What this means is that every action we take requires a command well in advance of it's execution, and we have visual feedback of it's completion well after. When we see our hand grasp the teacup, the message to do so was sent by the brain long ago, and the event was fully completed before we saw that it was so.
Our our subconscious is looking after the real time verification of actions - if no problem arises, our conscious is not informed. Our autonomic system deals with the precision timing without referral to our consciousness unless it is a complex task that we are not familiar with.
Mostly our conscious doesn't have to do much with the information - it'a all mundane stuff. If however, the act contains a sensual, moral or ethical component, then it will do a review of the outcome and decide in some form "It was good" or "It was bad". These post-event judgments are what largely shape our personality, and we have the ability to retrain them. Parents and 'superiors' have a lot of influence in our post-event judgments, as they often take the role of performing them for us, and telling us how we should feel or act.
By modifying our post-event judgements, we modify our future actions. We have absolutely no influence whatsoever on "Now", because it comes and goes in timescales that our conscious can't contemplate.
A final point to all this comes from Kant's 'Categorical Imperative'. The exercise of forming "I will..." statements is very much against our nature. Viturally all of our conscious decisions take the form of "I must...", or "I should...". There is usually consideration of a will other than our own (the boss, the family, the tax collector, etc.) At best we'll form the decision as "I think I'll...", or "I might..." which is our way of saying "I will..., if it's okay with everyone and allowing for the fact that I might fail."
I consider Free Will to be an artificial construct, a construct of an insecure consciousness, that causes more harm than good. A well trained subconscious and autonomic system will do a wonderful job of getting us through life, with the conscious enjoying the ride as a satisfied observer, called in to take control only when new experiences are encountered.
I mostly just get on with life as it presents itself. Sometimes (less than I used to) I waste precious time with regrets and remorse - reviews of the past structured in no way that can help me retrain for the future. Mostly I amuse my conscious with grand plans, dreams and philosophical musings. Occasionally I allow it to set the wheels of manifestation in action, and sometimes something appears in the real world as a result of my own deliberate thought - that is creativity.
Enjoy your day!
Cheers,
Craig