What drives a man to achieve his goals? Motivation of course!

The enthusiastic mindset that if you work hard, you'll achieve.
The unhindered perspective that compels you to think about the end goal and ignore the hardships that attempt to impede your progress towards greatness.
The idea that putting your best foot forward will gain the admiration of a metaphorical Hermes who will then grant you his winged sandals to propel you above the rest of your peers and out of your unsatisfactory situation.

What drives a man to succeed in his ventures? Motivation of course!

A burst of energy that says "I can do it if I believe I can." despite limitations on your strength or your intelligence or your character.
An aura that surrounds you and invigorates your humors, enticing your senses as well as giving you a mask that hides your unsure demeanor.
It's a revelation, that motivation, which enlightens the soul and frees the body from the chains that marked the end of it's abilities.

What drives a man to accomplish milestones for himself? Perhaps it manifests itself in something other than motivation.

It could be the desire to find acceptance, to be wanted, to get that simple thumbs up that sends a message that needs not be spoken. "You did well."
Possibly it would be the wish, the simple wish that a man will have done something worth remembering in the brief existence that he has, something he can look back on and think to himself, "I didn't do half-bad on that, did I?"
Teetering on the self-existential reflecting concepts, it could just be that man wishes to find fulfillment by filling his daily activities with anything. And that the greater the activity, the laborious hours put into completion, here man finds solace in putting meaning into his day to day living. Thus we find that goals are merely tick marks, road signs on the long drive from life's start to inevitable death.

This, this is all motivation. Anything that places reins over a man's mind and hits the spur against his brain, in hopes that this will help him move forward and do what he believes is necessary to do.

Motivation is to place one's self in this self-deprecating position as to be a slave to ambition in order to be satisfied with one's life. And to think that motivation is a blessing that leads to self-improvement.

Motivation is truly the mind's greatest illusion.