Your Constant Companion

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.

I am managed with care -- you must be firm with me. Show me exactly how you want something done, and after enough lessons, I will do it automatically.

I am the servant of all great people and, alas, of all failures.

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 the precision of a machine and the intelligence of a person.

You may run me for profit or run me for ruin -- it makes no difference to me.

Take me, train me, and 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?

I am habit!

Author Unknown