I've been thinking a lot about the little ways we see Garak's character change over time, just in terms of how comfortable he is talking about himself and his past. Like at the end of The Wire, he's saying "haha what's up with Odo thinking I was in the Obsidian Order, that's weird," and he knows Julian knows that he absolutely was, but they basically both agree to pretend he wasn't and not talk about it. But then by Our Man Bashir a couple years later, he's just directly saying "your spy fantasy is stupid and unrealistic and I know because I actually was a spy." At some point in the middle there he got more okay with acknowledging and discussing that.
Similarly, back in Past Prologue, he was responding to Julian calling him "Mr. Garak" with "it's just Garak," as if that's his entire name and not only a last name. In The Wire, he can only talk about "Elim" as if that was a different person. But by "Things Past" in season 5, he's talking about the name tag that said "Elim Garak, former Cardassian oppressor," and you might be distracted by how funny that is and not really think about how that means he told a whole bunch of people his first name! He was walking around with his full name on a name tag for strangers to read! That's so hugely different from a few years ago! It's just fascinating to me how some of these developments sort of take place offscreen, in between episodes, and Garak just shows up again being a little less cagey about his past and a little more comfortable with who he is the next time we see him.