Better get a stiff neck from aiming too high than a hunch from aiming too low. One cannot govern with buts. Do not be afraid to take big steps. You cannot cross a chasm in two small jumps. Some people walk in the rain. Others just get wet. The way to be safe is never to be secure.
Do not compromise yourself. You are all you have got. How was Einstein able to conceive the Theory of Relativity? He said the one crucial thing that helped him was his ability to visualise: what would it be like to be riding on the end of a light beam? You are never given a wish without also being given the power to make it true. You may have to work for it, however. Do or do not. There is no try. Only a mediocre person is always at his best. To avoid criticism, do nothing, say nothing, be nothing. You must have long-range goals to keep you from being frustrated by short-range failures. Once you make the fundamental choice to be the predominant creative force in your life, any approach you choose to take for your own growth and development can work, and you are especially attracted to those approaches which will work particularly well for you.