How I use LLMs

131 minutesBeginnerPractitionerAndrej KarpathyPrompt Engineering

Andrej Karpathy. Skip to the "ChatGPT memory, custom instructions" chapter at 1:53:29. Karpathy shows what he actually has in his own custom instructions, talks about when he tells ChatGPT to remember a fact versus letting it auto-capture, and notes the trade-offs — closer to the article's "set it up once with intent" framing than most beginner walkthroughs.

AI Expert note

The reasoning about durable preferences is solid; the exact memory behavior may differ by product version, region and workspace setting. Do not store confidential client, employee or legal details as "preferences."

What you should get from this

Understand how a power user separates durable preferences from one-off context.

Watch or know first

Know where custom instructions and memory live in your current ChatGPT settings.

Last reviewed: May 18, 2026

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