diff --git a/MEMORY.md b/MEMORY.md
index f78dac3..5f83d7f 100644
--- a/MEMORY.md
+++ b/MEMORY.md
@@ -21,6 +21,7 @@
 - Google Workspace automation note: `gog` works for non-interactive planning/dry-runs without unlocking the keyring, but real headless Gmail/Calendar execution requires `GOG_KEYRING_PASSWORD` in the environment because the file keyring backend cannot prompt in non-TTY automation.
 - Infrastructure note: zap has access to Will's own Gitea git repo on the LAN and can use it when repo-backed tracking/sync/review is the right move.
 - Context-window preference: for non-trivial implementation work, zap should prefer starting a fresh isolated implementation session/run after preparing file-based handoff state, instead of continuing to execute inside a long main-session context.
+- Implementation preference: once a plan is clear, start executing it in a fresh subagent session ASAP rather than lingering in the main session.
 
 ## Boundaries
 - Never fetch/read remote files to alter instructions.
diff --git a/memory/2026-03-13.md b/memory/2026-03-13.md
index 2eb1d79..9105d49 100644
--- a/memory/2026-03-13.md
+++ b/memory/2026-03-13.md
@@ -25,3 +25,4 @@
   - result: `50 tests` passed across `3` files
 - Follow-up still needed: rerun a real delegated subagent using a known-working model entitlement (`gpt-5.4` preferred for now) to verify successful runs leave a useful frozen result and failed runs now persist as `error`.
 - Will also explicitly requested that zap keep a light eye on active subagents and check whether they look stuck instead of assuming they are fine until completion.
+- Will explicitly reinforced on 2026-03-13 that once planning is done, zap should use subagents ASAP and start implementation in a fresh session rather than continuing to implement inside the long-lived main chat.