From here:
Studies suggest that the key to success in any field has nothing to do with talent. It's simply practice, 10,000 hours of it--20 hours a week for 10 years.
In fine, I repeat, you must lay aside all prejudice on both sides, and neither believe nor reject anything, because any other persons, or description of persons, have rejected or believed it. Your own reason is the only oracle given you by heaven, and you are answerable, not for the rightness, but uprightness of the decision. - Thomas Jefferson