What has the past ever done for me?

The teachers stands in front of the students, a keen but average group.
"Do we all know what a rhetorical question is?"
"What Sir?"
"Do we all know what a rhetorical question is?"
"Naaah sir. Tell us."
"Well, I will give you an example...What has the past ever done for me?"
"Oh right...I've got it....kind of ...
"Why are cigarettes sold in gas stations when smoking is not allowed there?"

"Is that it sir?"