Compared to other forms of entertainment, the pleasurable effects of music are less likely to wear off. People turn to a favorite album far more often than a favorite short story or favorite film. All entertainment experiences diminishing returns, but on balance, the returns from music are more consistent and stable than its competitors.
A telling example of this: You read a book in a bookstore so you don't have to buy it. You listen to an album in a record store (when they existed) to see if you want to buy it.
An average album doesn't "end" for you. The greatest book does.