Your Claude memory file is probably making it dumber. Anthropic just published how Claude's memory actually works, and they tested it on Pokémon Red: - Sonnet 3.7 saved everything: 413 files in 225 folders. It earned 1 badge - Fable 5 saved only what it couldn't see on screen: 9 files plus one global.md. It earned 4 badges - Opus 5.5 kept a few short notes and beat the game What they found: - Tell Claude what memory is for, not strict rules. Forcing "only record failures" wiped out much of the gain - Claude Code only loads the first 200 lines or 25 KB of MEMORY.md. Anything below that never makes it into the session - Longer instruction files make Claude follow them less - "Dreaming": letting Claude reread its old sessions to fix wrong notes. On a 350,000-file company archive, accuracy went from 13% to 48% The fix takes 2 minutes: open your CLAUDE.md or MEMORY.md, cut it under 200 lines, and delete anything Claude can already read from your code.