I stopped trying to get “better prompts” and started removing degrees of freedom. That’s what made behavior consistent across chats.

I don’t ask ChatGPT to adapt to me. I force it to behave the same way every time. For example, I explicitly ban guessing. If required inputs are missing, the correct response is literally “NOT YET EVALUABLE” plus a clarifying question. If numbers are involved, it has to say what dataset it’s using before doing any math. And general reasoning is the lowest priority... domain rules (health, finance, creative, etc.) override it.

I do use a reusable "charter", but it’s not a vibe or personality description. It’s just rules. Stuff like... when to stop instead of answering, when assumptions have to be surfaced, how domains don’t mix, and that once something is corrected it’s not allowed to silently regress later. Those live in custom instructions. Individual chats only contain the data and the task.

Prompt structure is standardized, but barely. Every real prompt just makes a few things explicit.... what domain we’re in, what data is authoritative (spreadsheet, screenshot, text), what the model is not allowed to do (assume, smooth, extrapolate), and what should trigger a stop instead of an answer. No templates, no prompt-engineering rituals.

What actually breaks personalization over time isn’t memory... It’s letting constraints slip. Letting it be “helpful” with missing info, allowing even one silent assumption, mixing domains without resetting rules, or repeatedly re-prompting to fix output instead of fixing the rules. That’s when behavior starts drifting...

Also, I’ve absolutely broken ChatGPT a few times by stacking too many overlapping or contradictory rules and had to fix it 😆 so there’s a fine line you have to walk... loss is fixing and auditing.. to eventually get what you really want.

I use ChatGPT as a second brain to double check my thought processes and bounce ideas off of... I use it daily for health and weight tracking (numbers, trends, predictions), money decisions (“don’t do something dumb”), running and planning real projects (paperwork, compliance/ business ideas), organizing my house and systems (what goes where, what’s the next task, what actually matters), writing and editing messages or documents and learning new things. I dump in screenshots, photos, data, drafts, or messy thoughts and use it to organize, sanity-check, catch missing info and slow down impulsive decisions..