I suggest you read The Killing Joke before watching, or read my summary below

Rating: 9/10 (3 February 2020)

The pannels that I believe will give the insight required to understand and enjoy the ending of the film:
"I MEAN, what IS it with you? What MADE you what you ARE? Girlfriend killed by the MOB, maybe? BROTHER carved up by some MUGGER? SOMEthing like that, I bet. SOMETHING like that... Something like that happened to me, you know. I... I'm not SURE what it was. Sometimes, I remember it one way, sometimes ANOTHER... If I'm going to have a PAST, I prefer it to be MULTIPLE CHOICE! HA HA HA!"