Characters
If I'm not back in five minutes... just wait longer!
— Ace ‧ Ace Ventura: Pet Detective

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
Speaker tells someone that if five minutes pass without a return, the sensible response is simply to wait more. It is a deadpan non-instruction, treating a long absence as no cause for alarm or rescue. The humour comes from the reversal of the usual promise of a deadline.
Context reviewed