Context Windows: Why Your AI Sometimes Forgets What You Said Earlier

Imagine you're talking to a tutor in a room where there's a door behind them. Every time someone walks through that door, the tutor forgets the oldest thing you said. The bigger the door, the more things they can remember. That door is called a "context window."

A context window is the amount of conversation AI can "see" at one time. Think of it like the tutor's working memory. Inside that window, the AI remembers everything. Outside it, the AI genuinely forgets.

Why This Matters for Learning

If you're learning something complex—say, building a concept map for your philosophy essay—you might have a long back-and-forth conversation. Early in the conversation, you explained your main argument. Halfway through, you might say "how does this connect to my thesis?" If your conversation got too long, the AI might have forgotten your thesis completely. You have to explain it again.

This isn't the AI being bad at its job. It's a technical limitation, like how a human can only hold so many items in their hands at once.

Different Tools, Different Windows

• Claude: Very large context window (100,000+ tokens—roughly 75,000 words)
• ChatGPT: Medium-large context (up to 128,000 tokens in recent versions)
• Gemini: Large context window (1 million tokens in some versions)

One token is roughly one word. So Claude can "see" about 75,000 words of conversation at once. That's a lot, but a long study session with multiple topics can exceed it.

How to Work Around It

Start fresh conversations when you switch topics significantly. Summarize key decisions at the start of a new conversation: "I'm building a study plan for organic chemistry. I learn best through analogy and practice problems. I have 4 weeks." This re-establishes context quickly.

Try this: Have a long conversation with an AI about a complex topic (at least 20 exchanges). Then ask it to summarize something from your first few messages. If it struggles or gets details wrong, you've hit the context limit. Note the conversation length, then you'll know your practical limit for that tool.