Quote

“[Ben Affieck] got back on the horse, but I’ve just been running around working.”

Matt Damon, talking about getting back into writing movies instead of only acting in them.

Meaning

Try again or keep trying to do something

Use

Have you ever tried to do something and failed? Maybe you tried to make a delicious meal but it didn’t turn out right. Maybe you spent years writing a book and then just gave up because you didn’t think it was any good. Well, you need to get back on the horse and try again.

To get back on the  horse means to try again at doing something

Matt Damon and Ben Affleck were old friends living in Boston. They were trying to become actors, but they couldn’t get a break. So, they decided to write their own movie, Good Will Hunting. The movie was a huge success, and the two actors became very famous.

Matt thinks of himself as a writer, but he ‘s been so busy acting in new movies that he hasn’t had time to get back on the horse and try writing again.

Examples

“My first song was a failure, but I got back on the horse and recorded another one.”