Mistakes are the portals of discovery.

Courage is doing what you're afraid to do. There can be no courage unless you're scared.

If you only knock long enough and loud enough at the gate, you are sure to wake up somebody.

Men take only their needs into consideration, never their abilities.

The history of the world is but the biography of great men.

Ability is of little account without opportunity.

Success is the prize for those who stand true to their ideas.

Keep your business affairs in your own hands. It's the only way to be happy.

Your dream is your belief. It is your faith, which will put the action behind it.

Don't let the storm take the wind out of your sails.

Well, the one motivational saying I often attach to my signature is one of Benjamin Franklin's many gems:

“Tomorrow, every Fault is to be amended; but that Tomorrow never comes.”

Here are some motivational quotes quoted by some famous people:

Have patience with all things, but chiefly have patience with yourself. Do not lose courage in considering your own imperfections but instantly set about remedying them - every day begin the task anew. - Saint Francis de Sales, 1567-1622

Courage and perseverance have a magical talisman, before which difficulties disappear and obstacles vanish into air. - John Quincy Adams, 1767-1848

Make no little plans; they have no magic to stir men's blood...Make big plans, aim high in hope and work. - Daniel H. Burnham, 1846-1912

Guard well within yourself that treasure, kindness. Know how to give without hesitation, how to lose without regret, how to acquire without meanness. - George Sand, 1804-1876

Always laugh when you can. It is cheap medicine. - Lord Byron, 1788-1824

The secret of a good life is to have the right loyalties and hold them in the right scale of values. - Norman Thomas, 1884-1968

The person who makes a success of living is the one who see his goal steadily and aims for it unswervingly. That is dedication. - Cecil B. DeMille, 1881-1959

Cherish all your happy moments: they make a fine cushion for old age. - Christopher Morley, 1890-1957

Be not ashamed of thy virtues; honor's a good brooch to wear in a man's hat at all times. - Ben Jonson, 1572-1637