THE POWER OF HABIT

You may know me.
I'm your constant companion.
I'm your greatest helper; I'm your heaviest burden.
I will push you onward or drag you down to failure.
I am at your command.
Half the tasks you do might as well be turned over to me.
I'm able to them quickly, and I'm able to do them the same every time if that's what you want.
I'm easily managed, all you've got to do is be firm with me.
Show me exactly how you want it done; after a few lessons I'll do it automatically.
I am the servant of all great men and women; of course, servant of the failures as well.
I've made all the great individuals who have ever been great; and I've made all of the failures too.
But I work with all the precision of a marvelous computer with the intelligence of a human being.
You may run me for profit , or you may run me to ruin; it makes not difference to me.
Take me.  Be easy with me and I will destroy you.
Be firm with me and I'll put the world at your feet.

Who am I?
         I"m Habit!