Twenty minutes, once. Answer in plain language, like you are briefing a sharp new hire. The result is a FOUNDATION.md file: paste it into your AI tool's project instructions (or at the start of a conversation) and it stops guessing who you are.
Download it, keep it with your business documents, and paste the contents into your AI tool: project instructions in Claude, custom instructions or a project in ChatGPT, or simply at the top of an important conversation. Update it when your focus changes.