Who Am I?

 I am your constant companion.
 I am your greatest helper or heaviest burden.

 I will push you onward or drag you down to failure.
 I am completely at your command.

Half of the things you do you might as well turn over to me and
I will do them – quickly and correctly.

 I am easily managed – you must be firm with me.
Show me exactly how you want something done and after a few lessons,
I will do it automatically.

I am the servant of great people, and alas, of all failures as well.
Those who are great, I have made great.
Those who are failures, I have made failures.