Perseverance

This is a well known phrase, but, however, I think it's worth sharing it:

"When nothing seems to help, I go look at a stonecutter hammering away at his rock perhaps a hundred times without as much as a crack showing in it. Yet at the hundred and first blow it will split in two, and I know it was not that blow that did it, but all that had gone before."

Jacob Riis

Spanish version:

"Cuando nada parece ayudar, voy y miro a un picapedrero, dedicado a golpear su roca quizás cien veces, sin que en ella aparezca una sola grieta.
Sin embargo cuando da el golpe ciento uno, la roca se parte en dos, y yo sé que no fue ese último golpe el que la consiguió partir, sino todos los que había dado con anterioridad."

Jacob Riis