Luck marches with those who give their very best.
The best preparation for tomorrow is doing your best today.
Life doesn't require that we be the best only that we try our best.
If you're doing your best you won't have any time to worry about failure.
If I'm not writing well I'm not happy. If I'm not spending enough time with my family I'm not happy. If I'm not connecting to friends or if I don't work out enough... You get the point. Everything has to be balanced. Nothing should be an extreme.