"It is one of the most inspirational Talmudic stories, related in Avos D'Rebbe Nosson. Rabbi Akiva was a shepherd, a laborer, an am ha’aretz – religious in observance, but ignorant of Torah knowledge. At age 40, he didn’t even know how to read the aleph-beis.
One day, while sitting by a brook, Akiva noticed a steady trickle of water hitting a rock. It was only a drip, but it was constant – drop after drop after drop. Akiva observed something incredible: A hole had been carved out by that steady drip of water. He wondered how that could be. He concluded: If something as soft as water can carve a hole in solid rock, how much more so can words of Torah – which is compared to fire – make an indelible impression on my heart."
Avot d'Rav Natan 6
Text found on Aish.com. From the Artscroll book "Like Water on a Rock."