Why don't good horses turn to grass? (brain teaser)

The answer is: A good horse doesn't eat grass back, which means eating all the way, and the grass behind it is eaten by the horse.

explanation and analysis: this question is a brain teaser. It asks "What does a good horse mean if it doesn't turn back?" Because the conventional "good horse doesn't turn back" means that an ambitious person will never turn back even if he is frustrated.

However, brain teasers can't be solved by conventional thinking, so the problem can be regarded as a way to make the horse stop eating grass, and the way to make the horse stop eating grass is that there is no grass, so only when the grass behind it is eaten by the horse can the horse stop eating grass.

Extended information:

The thinking of brain teasers needs to leave the habitual thinking quickly and think about the problem from other aspects when the thinking encounters special obstacles. For example:

What books have the most mistakes? The answer is: medical books.

explanation and analysis: this is a brain teaser, which asks, "What book has the most faults?" And the answer is to guess a number by guessing, because the mistakes in the book have two meanings, one refers to the mistakes in the book itself;

The second kind is the "faults" recorded in books, which is more in line with the brain teaser's idea of solving problems, because all the contents recorded in medical books are to cure all kinds of "faults", so "medical books" have the most faults.