This could mean a reference to the daily grind of work. But work is actually fun, so that’s not it. Grind could be in reference to grinding coffee, which I like extremely. Could be likely. It’s actually a song by Phish that’s stuck in my head right now.
I can bend in sixty-eight ways
I have lived for twelve thousand days
Twenty-eight teeth inside my head
Grind three types of things and I’m sad that they’re dead
Derek Kiernan Gebler 