What triggers a flash of actual nostalgia is a memory of the days when you met someone in the real world, perhaps at an activity that both of you enjoy, perhaps someone who wasn’t even supposed to be your type. That person might have caught your fancy, and the first order of business was to figure out whether he or she was, like you, unattached.Honestly people, you can still do this. Nothing's stopping you.
You know what my best "dating site" has actually been? Facebook events. Whether it's something public, a meetup, or friends' parties and the like, I meet people who know people and sometimes those people are attractive and then I ask them if they want to go out sometime.
I have gotten more dates that way in the last 6 months than I have in the entire history of using online dating websites. The whole experience, even in its' ideal, is so utterly artificial, compared to just meeting someone in person. I am on the verge of just dismissing the concept as a sham. They seem to exist mostly as an outlet for desperate men to harass women in bulk volume.
I still glance at Tinder occasionally, and I have an OKC subscription I keep forgetting to cancel, but in the former case it's become little more than a mobile version of "Hot or Not" to play when I am bored (the rare response is almost always spam), and in the latter it's more of a "well, if I hit a lull, maybe ..." sort of a thing.
I'd much rather just meet actual humans face to face and give us both a chance to see what we're really like in person. That's where a natural connection is going to come from anyway.