How to Keep Your Messages Forever

I don't have all of my iMessage going back to forever, which makes me feel like at some point I must have had some kind of failed device migration or I decided to set it up as new. There's messages in the cloud and when did that come in and what's that going on? No, I just scrolled back to a text message thread with a friend and it goes back to November 2012, that thread. That's my earliest message that I have forever, baby. Unless you're committing crimes.