What seems to almost be some sort of trope nowadays is people being self-deprecating about the clothing, hairstyle and music they used to really enjoy. A common one I see is people talking about their "emo phase". Only, it wasn't a "phase". A phase is a transformative period, and simply enjoying things is not transformative, it's your tastes. It's the things that make you happy.

But maybe you didn't really enjoy it, and what you are really trying to say is that you went through a "flaky teenager trying to impress people by wearing what was considered "cool" phase", which is what many people do when they're still in the process of maturing and developing a sense of identity - if they ever do. THAT is something to be embarrassed about, once you've outgrown the desire to define yourself by others' opinions.

But if it was something you genuinely liked, and you've just shifted your focus on other interests since then, what the hell are you on about? Who are you trying to impress? Assholes who shame people for liking things that aren't popular (or things that are, which is just as bad) ? People who currently enjoy what you used to be really into may become discouraged by your shitty remarks, and then feel like they need to be ashamed of their own joys. Is your self-deprecating joke really worth the risk of trampling over someone else's happiness? Unless it's hurting someone (and that includes socially or psychologically) it's really dickish to yuck people's yums, even your own.