"I am not what I ought to be, I am not what I want to be, I am not what I hope to be, but I thank God I am not what I once was. By the grace of God, I am what I am"
"What I ought to be": this is the standard defined by God or by others.
"What I want/hope to be": this is the expectation or longing for from myself.
"by the grace of God, I am what I am": with a thankful heart to accept what I am at now.