Personalize ChatGPT: your own instructions, memory or your personality profile?

If you use ChatGPT a lot, you notice it quickly: the answers are good, but generic. The model doesn't know you. That's why so many people keep typing the same explanation about themselves. "I like to plan ahead." "I don't like long texts." "Give me the answer first, then the explanation."

There are three ways to personalize ChatGPT: write your own instructions, let it build up a memory, or connect your personality profile. They work well together, but each does something different. Below, we compare them side by side. Most of this applies to Claude and other AI assistants too.

1. Writing your own instructions

In ChatGPT's settings, you can describe what it should know about you and how it should respond. That then applies to every new conversation.

Pro: you decide exactly what goes in. For practical preferences, this works brilliantly: your job, your language, how long answers should be, whether you want bullet points.

Con: you need to be able to describe yourself well. And that's exactly the hard part. Most people write down how they like to be seen, not how they actually make decisions or react under pressure. And a few sentences rarely capture your whole personality.

Tip: with the connection from the third way, you don't have to write that text yourself. Ask your AI assistant for instructions based on your personality profile and paste the result into your settings. Then ChatGPT knows in every conversation how you want it to respond.

2. Letting it build up a memory

ChatGPT can remember what it learns about you from your conversations. The more you talk, the more it knows.

Pro: it happens automatically and gets richer the longer you use it.

Con: the memory only knows what happened to come up in your conversations. It's a collection of loose facts, not a coherent picture. And it's hard to keep track of what exactly has been remembered. On the plus side, you can view and clear the memory.

3. Connecting your personality profile

The third way is to connect your personality profile as a source via MCP, an open standard for connecting tools to AI assistants. With the Personal User Guide AI connection, ChatGPT or Claude fetches your profile whenever your question calls for it.

Pro: the profile comes from a personality test based on the Big Five, not from your own description. It describes your preferences on five dimensions: how you deal with new ideas, how you plan, what gives you social energy, how direct you are and how you handle stress. Your AI assistant uses that in every piece of advice, from a holiday to a difficult conversation. It also adapts the tone and format of its answers: short or detailed, conclusion first or ideas first, direct or careful. If you retake the test later, your AI assistant automatically reads your new profile.

Con: you have to take the test first, which takes about ten minutes. And your profile is sent to the AI provider when your assistant fetches it. Their privacy policy applies to that, just as it does to whatever you type yourself.

Which one should you choose?

Use them together. They complement each other:

So put the practical things in your instructions: your language, your work, the format of answers. Let the memory keep track of the facts. And connect your personality profile for the part that's hard to put into words yourself: who you are. Curious what difference that makes? In six examples of AI advice that suits you, you can see it for yourself.

Frequently asked questions

How do I let ChatGPT know who I am?

You can describe yourself in the settings, let it build up a memory or connect your personality profile via MCP. Instructions and memory capture what you tell it yourself. A connected profile comes from a personality test and describes how you work, decide and communicate.

Does this work for Claude too?

Yes. Claude also has settings for your own preferences and a memory feature. You connect a personality profile in Claude the same way as in ChatGPT, as a custom connector with the Personal User Guide server URL.