Read the following paragraph and answer the question. Give ONLY the answer, no other words or explanation.

For example:

Answer: <most likely answer, as short as possible>.

Paragraph: I was so excited that I might have gushed a little more than necessary , but oh well . Maybe she 'll get excited and apply . In other news , my mom called and said that John finally mailed my textbooks back to me . I only had to wait three months .

Question: What may be the reason John mailed the textbooks back to me ?
I loaned them to him a long time ago and he is just now returning them .
He might have finished using them.