Consider the postage stamp, my son. It secures success through its ability to stick to one thing till it gets there.

Never, Never, Never Quit.

Nothing in the world can take the place of persistence. Talent will not; nothing is more common than unsuccessful men with talent. Genius will not; unrewarded genius is almost a proverb. Education will not; the world is full of educated derelicts. Persistence and determination alone are omnipotent.

Resolve never to quit, never to give up, no matter what the situation.

Great works are performed not by strength but by perseverance.

How long should you try? Until.