Energy and persistence conquer all things. - Benjamin Franklin
Though Ben Franklin said this over 200 years ago, it is still true today. Often we give up and stop trying right before we're about to have a breakthrough. Keep at it, and you will succeed.
Here are a few failures who never quit trying:
I'll close with one last quote, from another famous guy you might have heard of:
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. The slogan “Press On” has solved and always will solve the problems of the human race. - Calvin Coolidge