It was in a chat with Anton from SBW and fiatjaf where we were discussing sending sats to an email-like interface. That conversation sort of died out, until fiatjaf and I on a random Friday decided to revive it and with the help of Hampus and Fitti (and many other folks whose names I don't remember atm) we arrived at the spec for LUD16: https://github.com/fiatjaf/lnurl-rfc/blob/luds/16.md.

That same weekend I built https://lightningaddress.com. The following Thursday I announced the protocol at BitDevs NYC.

At that point, we had ZBD, LNTXBot, SBW, and Blixt Wallet who said would implement support for this interface for sending sats, but only LNTXBot and ZBD could serve Lightning Addresses for their users (custodial servers).

Now everyone has support for sending and/or receiving LN Address payments, with lots of innovations on the way as well. Now my podcasting app can send and receive money to my bitcoin neobank provider. How cool are standards?