# Lesson 2 complete; storage-event and availability still soft

Learner finished lesson 2 (Storage API & events). Strong on JSON/`setItem`, `getItem` → `null` for missing keys, and localStorage cross-tab events. Two misses to reinforce in later practice:

1. **Scenario C (sessionStorage + storage event):** Other same-origin tabs do **not** receive `storage` for a `sessionStorage` write; the writing document does not either. Only other documents that share that session map (e.g. same-tab iframes) can. Do not treat sessionStorage as a multi-tab bus.
2. **Scenario E (availability):** Presence of `window.sessionStorage` / `typeof` is not enough — MDN’s sound check is a try `setItem` + `removeItem` probe (with quota-exception nuance). Policy and private mode can block writes.

Implications: lesson 3 deal-breakers should interleave multi-tab/event myths and “always available” assumptions; do not re-teach the full method map from zero.