Man is a pupil, pain is his teacher.
Alfred de Musset

It's not because things are difficult that we don't dare.It's because we don't dare that things are difficult.
Seneque

The wise man asks himself the reason of his mistakes.The fool asks others.
Chinese proverb

By trying often, the monkey learns to jump from the tree.
Cambodian proverb

With time and patience, the mulberry leaf becomes silk.
Chinese proverb

Life's battles don't always go to the stronger or faster man, but sooner or later the man who wins is the one who thinks he can.
Bruce Lee