Explanation: metaphorically speaking, people who do things don't go back.

Source: Lu Yao's Ordinary World, Volume III, Chapter 32: "A good horse doesn't eat grass. Now that he has left his nest, he is determined to wander in the outside world. "

Since I chose to resign, I don't care so much.

Usage: as object and attribute; Used in spoken English

The allusion of "A good horse never eats grass again" is that a good horse walks out of the stable and rushes to the vast grassland, where he can catch a glimpse of delicious tender grass at a glance, so he eats along the selected route until his stomach is big and round, and he will never take a bite from the east and a bite from the west, and then go back to make up for the missed tender grass. In other words, not all the grass behind us is bad, nor all the grass in front of us is good. It's just that a good horse will carefully eat the grass in front of him, so there is no' turning back to the grass'. Many times people just use this sentence to make an excuse for themselves. But it belongs to a neutral proverb, which neither praises nor derogates.