Who or What Am I?
 ~ By, Anon Y. Muss ~

I am your greatest helper, Or your heaviest burden.
I will push you onward, 
Or I'll drag you down to failure.

I am at your command.

Half the tasks that you do, 
You might just as well hand over to me.
I will do them quickly and correctly.

I am easily managed.

You must merely be firm with me. 
Show me exactly how you want something done.
After a few lessons, I will do it automatically.

I am the servant of all great people. 
And alas, of all failures as well.

Those who are great, I have made great.
And those who are failures, I have made failures.

I am not a machine.
But I work with all the precision of a machine.
Plus the intelligence of a person.

You may run me for profit, or run me for ruin.
Makes no difference to me!

Just take me, and train me, and be firm with me
And I will lay the work done at your feet.

But you be easy with me, and I will destroy you.

Who or what am I?