I just look around and see what everybody else is wearing. That gives me a pretty good clue of what's in/out.
That's the rub to my mind. Part of me is thinking it's mostly (as several posters have mentioned) about localized subcultures and tribes as to whether the era of an item allows you to blend in or not. It's possible to wear a look that hit peak popularity in the biggest urban areas years or decades ago, and still fit in quite well and gain approval within your localized community or workplace -- because that is what other people around you are wearing too. If it works, why change? Especially when change poses risks.
Then there is the global online community, and the fashion tastemaker community which might be geographically somewhat scattered, but still flys in for fashion week or has a bit of hive brain when it comes to making retail buying decisions. They might be far ahead on the fashion evolution timeline compared to most folks who are more likely to think local rather than global in terms of belonging.
If these looks continue to be worn at the same time in different places, depending on context, then why does it matter? Why not just take local cues? But I'm thinking it can matter, because it can have to do with power.
In the Melissa McCarthy film 'Spy' (which is awesome) she is a US agent going uncover in Europe, but she keeps being underestimated by her government employers and given cover identities that involve the frumpiest clothing and wigs, and backstories like 'cat lady from Nebraska' so that she can be effectively invisible doing her job.
But she doesn't want to be invisible. She's brilliant and competent and has been overlooked for far too long and she sees the male agents James Bond-ing around in their bespoke suits and wants that respect. She wants to be listened to, taken seriously as a player, and to be a bit glamorous as well. One of the first things she does is to ditch the costume and buy a stunning black dress and her style evolution continues in fits and starts throughout the movie as she takes more and more control of the operation. You can see how her clothes do change how others react to her, but also more importantly, how they support her and armor her with confidence.
Anyways I'm rambling, but thinking about the power inherent in clothing that communicates 'of the moment' globally. How do you communicate 'of the moment' when wearing clothes or picking up stylistic attributes from an earlier era? I think it's like contemporary art -- it has to do with who is the audience and what is the intention, and how the players are already involved in the current conversation and self-aware that they are responding to history, not recreating it.
