Although the author is unknown, "Shonen oi yasuku gaku nari gatashi" (少年老い易く学成り難し) means that young people tend to think they have plenty of time and don't apply themselves to their studies, but time quickly passes and they grow old, ending up without having learned anything. Therefore, one must strive to study from a young age. "Issun no kōin karonzubekarazu" (一寸の光陰軽んずべからず), from the same source, is also used as a proverb.