A yojijukugo for going back to school.

温故知新
on.ko.chi.shin

Literally: warm – reason/cause/therefore – know – new

Alternately: Learning from the past. Gaining new knowledge or wisdom through (thorough) study of the past. Moving forward with new ideas, based on studying the past.

Note: It would seem logical to use 古 (meaning “old,” and also pronounced ko) in place of 故, but this is incorrect. The roots of the phrase are actually in a Confucian pronouncement which uses the character 故.

The joy of scholarship. It’s there, trust me.