The Oxford Dictionary originally defined it as “acute homesickness.” Later, it evolved into “a sentimental yearning for the happiness of a former place or time.” These days, it’s more commonly understood as, “a sentimental longing or wistful affection for the past, typically for a period or place with happy personal associations.”

No matter how you define it, nostalgia is rooted in one thing, longing for the past.

And it comes in more flavors than your favorite childhood cereal. There’s personal nostalgia, cultural nostalgia, collective or historical nostalgia, even anticipatory nostalgia (yes, that’s a thing). Some experts break it down even further into categories like physical, social, time-period nostalgia, lifestyle appeal, savoring the moment, and the ever-fascinating split between restorative vs. reflective nostalgia. Each one hits differently, but they all pull on the same emotional strings.

So, buckle up. Or better yet, grab your slap bracelets, push play on that mixtape, and let’s take a quick trip down memory lane.