"Beauty does not linger, it only visits." From Beauty: The Invisible Embrace (rediscovering the true sources of compassion, serenity, and hope) by John O'Donohue.
How much energy is wasted trying to make permanent something that is ruined by permanence?
The beauty of teaching is in the moment where a student is changed, truly changed for life. Much is written about making students more engaged and certainly an engaged student is better off than one that is not. It is truly impossible to teach a student that is drunk or high or otherwise impossible somewhere else while still being in your room. That said the beauty will still be in the moments, not in the day to day. The better we do the day to day the more likely the moments are to come, but by their very nature these moments do not linger.