future-3
Explanation
This comic features a time-travel scenario where someone from the future approaches a person and urgently tells them to stop doing something -- apparently harassing or being rude to people. The present-day person is confused, and the future visitor explains that in the future, this person's behavior has become well-known and problematic. The twist is that the person from the future is actually the older version of the same person, trying to warn their younger self.
The humor comes from the subversion of the typical time-travel warning trope. Usually in movies, future visitors come back to prevent catastrophic events like wars or assassinations. Here, the future self has come back simply to tell their younger self to stop being a jerk to people -- suggesting that this person's interpersonal behavior was so terrible that it warranted time travel intervention. The "dodgy future self" twist adds another layer, implying that even in old age, the person hasn't fully reformed.