Rashi On Youth

Ecclesiastes 12
1 Remember now thy Creator in the days of thy youth, while the evil days come not, nor the years draw nigh, when thou shalt say, I have no pleasure in them;

Rashi From Chabad.org
Reflect upon three things.  Remember your Creator that you will give an accounting and reckoning before Him; and remember your pit, your grave, a place of earth, maggots, and worms; and remember your well, the well that flows from its source: that is the putrid droplet of seed and semen.

One regret in life. Somehow I wish I had truly understood this verse thirty years ago. Then again, now, this passage is loaded with thirty years of meaning....