With great discipline and effort, we can better ourselves, but we cannot remake ourselves.
We can improve our physical fitness, our character, education, and career. But ultimately, we are not the masters of ourselves. There are limits to what we can change about ourselves. There is such a thing as raw talent, and no amount of practice and training can grant it. Everyone has natural strengths and weaknesses. Be careful that you do not allow your pride to make you think that you can remake yourself. If you try too hard, you will find yourself exhausted, and your self-esteem will plummet. There are limits to what you can change about yourself, and these limits remind us that we are not God - we cannot make ourselves into something other than what He created us to be.