There’s really no non-awkward way to tell the New Person that a particular, seemingly innocuous, thing you love — say, llamas — is actually an odd emotional remnant of your previous relationship, and that you associate any and all llama-based entities with Person the Former. So when New Person very sweetly shares some llama lore, you immediately, reflexively, think of another guy.
I love that you thought of me, though, really! Don’t worry, we’ll have a “thing” eventually. The llama thing didn’t happen until he and I were 5 years in. Inside jokes need to develop and be honed over time. We’ll get there, I promise!
P.S. I didn’t tell him any of this. I’m not an idiot.