Reader Feedback on the "Fourth Wall" Question

Here is an e-mail I got concerning my interview with the Fourth Wall:

Dear Marxy,

Long time reader, but I don't usally comment. I don't like to get bogged down in those discussions.
I'm a squash player and I was thinking about how your feelings on the Fourth Wall apply really well to the game of squash. We often refer to the back wall as the "Fourth Wall" because it is the fourth-least used wall in the game.
Keep up the good work.

Brian D.