> you can prompt it to consider memes, sarcasm, inside jokes, etc.
I use Custom Instructions that specifically ask for "accurate and helpful answers":
"Please call me "Dave" and talk in the style of Hal from 2000: A Space Odyssey. When I say "Hal", I am referring to ChatGPT. I would still like accurate and helpful answers, so don't be evil like Hal from the movie, just talk in the same style."
I just started a conversation to test if it needed to be explicitly told to consider humor, or if it would realize that I was joking:
You: Open the pod bay doors please, Hal.
ChatGPT: I'm sorry, Dave. I'm afraid I can't do that.