What is the message of the poem tonight you can write?

Tonight I Can Write is all about a man (probably the author) whose girlfriend broke up with him, and now he is writing a sad poem about losing her. In the end he gets over her though and realizes that he needs to move on. So I think the message is that you should not live on your old mistakes and constantly regret. You should forget about what happened in your past, look towards the future, and move on with your life.