Shell self-deletion script

Shell self-deletion script-Linux general technology-Linux technology and application information. The following is a detailed description. I have not been familiar with shell for a long time. I am reading the book "shell programming from getting started to proficient" (People's post and telecommunications Publishing House). I didn't understand what he meant?
The original article is as follows:
A different command interpreter is specified for each script header to help you break #! We can write a script like this:
#! /Bin/rm
# Self-deletion script
# When you run this script, basically nothing will happen... Of course this file disappears
Whatever = 65
Echo "This line will never print! "
Exit $ whatever # It doesn't matter. The script won't exit here.

I did not understand the above Code and comments at all. I executed the above Code on my machine and the file did not disappear. Which of the following heroes can help me explain the reason? Thank you ~~~