Be not afraid of going slowly; be only afraid of standing still.

Be not afraid of growing slowly, be afraid only of standing still

Be not disturbed at being misunderstood; be disturbed rather at not being understanding

The person who says it cannot be done should not interrupt the person doing it

If you don't want anyone to know it, don't do it

Do not anxiously hope for that which is not yet come; do not vainly regret what is already past