What does Mr. Mu Xin's poem "lend it to me" mean?

Every sentence is a regret that can't be obtained, and there is nothing. Even if you have a short time, you still have to pay back the word "borrow", and you will always be empty-handed. There are also memories of the good old days, such as blaming and complaining about your lover. Of course, it can also rise to the truth. Why not give a complete life?