参考答案： Self-improvement
As the saying goes, "There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self." Self-improvement is the key to a successful and rewarding life, for it means endless progress and permanent life pursuit. Constant competition with others can, in most cases, trigger negative feelings. Winning the competition may result in dangerous complacency, a recipe for future failure. However, failing to catch up with others may generate a pang of envy, eventually harming no one but oneself. Hence, it is much safer to compare with oneself.
Self-improvement is an endless journey. One can always be better. Physically, one can participate in more workouts, thus having a better shape to handle daily chores; spiritually, the most important task for people is to find the true value of life by reading books in various fields; socially, one can walk out of the routine life to make new acquaintances and broaden social circle.
To sum up, self-improvement is a fantastic way to a fruitful life. Accumulating on a daily basis, even a small improvement will have astonishingly magical power over fife.