Nostalgia is a powerful force that can make you look fondly on past things and events, even if parts of the past weren't so great. If it feels like everything marketed to you is based on nostalgia these days, it's no coincidence, but it's not all bad.
As the video above from TED-Ed explains, like most mental conditions, nostalgia has had a confused history in the psychological field. It was first noted in the 17th century by a medical student examining Swiss mercenaries serving abroad. At the time, it was thought that soldiers symptoms including fatigue, insomnia and fever were all caused by their shared desire to be back in their homeland. While none of those symptoms actually correlate with nostalgia, it was enough to give the feeling a name.
In modern psychology, our ability to study the feeling has become more practical. Researchers are able to examine the effects that something from a subject's past has on them when they haven't seen it in a long time. Unsurprisingly, if you discover something you enjoyed again, you have a rush of positive feelings.
That modern research informs advertisers who have caught on to the powerful feeling of nostalgia. It's much easier to make someone feel positively about something that they have encountered and enjoyed before, rather than to convince them to try something new.
Of course it's easy to get cynical and assume that this means we all consume junk and no one likes new stuff, but that's not totally true either. Advertisers still inundate us with franchises that are new (or at least new to most of us) all the time. Which reminds me, I still need to catch up on Westworld, Black Mirror and a million other shows I'd never heard of before. Still, nostalgia is a powerful force and now we know marketers have figured out how to use it, so it's worth keeping an eye out for. Just because you remember something from your past doesn't mean the reboot is going to be good.
Why do we feel nostalgia? [TED-Ed]