This isn't the first time, nor will it be the last: the only reason I'm actually using iCloud Keychain is because, despite always turning it off and feeling like I needed to keep doing it over and over again every time I got a new device, one day I was in a discussion with someone about it and I went to show them how I turn off most of the iCloud features, and I discovered I had actually failed and now had already been using iCloud Keychain and so all my passwords were already in it.