Who Am I? ..a riddle..
I am easily managed--you must merely 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 all great individuals and, alas, of all failures, as well. Those who are great, I have made great. Those who are failures, I have made failures.
I am not a machine, though I work with all the precision of a machine plus the intelligence of a human. You may run me for a profit or run me for ruin--it makes no difference to me.
Take me, train me, be firm with me, and I will place the world at your feet. Be easy with me and I will destroy you.
Who am I?