The AI forgets what I said at the start of a long chat. Does it have a memory limit?
Shared space: System prompts, conversation history, files, and response space all share the same total context window limit.
Output truncation is separate: Input context and max output tokens are separate (output truncation is usually due to reaching the output limit, not necessarily a full window).
Bigger isn't always better: A larger window doesn't mean you can cram everything in—irrelevant material dilutes the AI's attention and causes it to drift.
Before continuing this task, list the rules, files, and recent decisions that must remain, then compress older material into a short working brief. Show me that brief and the material you recommend excluding for confirmation before proceeding; do not assume you can delete the current conversation.