Two devices editing the same note while the connection is down. Right now the laptop and the phone hold different text and a pile of queued operations. Hit Reconnect and watch them merge — no prompts, no "which version do you want", no lost characters.
Why it always converges: every character gets a unique id like
L:14 and permanently remembers which character it was typed after, so
both devices rebuild the exact same order from the same set of operations —
whatever order those operations happen to arrive in.