So for this one, we are eyeballing millennials with a little bit of scope on either side.

You’ve probably had the universal experience regardless of the age group you fall into, though. You hear a song, and it has to be at least 15 years, if not more, since it last crossed your ears. As if you had stepped into a time machine, you’re back there. Wherever there is. You start thinking of the people, sounds, and what you were doing… Who you were at that time is suddenly at the forefront of your mind.

And while you didn’t know they had been filed away, you still know the lyrics.

That is the Sleeper Agent song.

Many newsletters ago, we covered sticky decades. But in short, it means that the music we hear between the ages of 10 and 30 (with some allowance for outliers) encodes differently for us. Researchers call it the reminiscence bump.

What makes these memories cool is that they are more vivid, quicker to recall, carry a bigger emotional weight - and most importantly, happen without warning. You can live for 15+ years with these ‘forgetten’ things, and suddenly you’re thrown into the past.

Research from the NIH found that music-evoked autobiographical memories are more episodically rich than memories triggered by almost anything else. More specific. More physical. More there.

And then there's the disappearance. A song you heard every day for a year and then never again for twenty years has been sitting in your memory completely undiluted. No ‘madee for you’ playlist cycling it back, because you never typed it in or added it to a playlist. No new associations piled on top. A sealed, perfect version of a moment. A luxury.

When you do hear it, it sweeps you up with full force. You really can’t help it.

That's not nostalgia, how we usually think of it. Nostalgia is warm and gentle. This is precise. Like a slap on the forehead. Like the opening note on Welcome to the Black Parade.

Maybe one of the coolest things about most of the songs on the playlists below is that they were around before we were drip-fed releases so heavily by algorithms. Sure, we had music streaming/stealing via Napster (LimeWire, Kazaa, etc.), but they never told us what we needed to listen to. We had to find it.

A couple of excellent songs that might’ve left your ears for a while. We’re not claiming that you don’t already have these particular ones on repeat, or that they are actually any good (though there are a couple of great tracks on there).

Some are pure cheese, and if released now, probably wouldn’t survive the rigors of the charts and attention spans.

Cheese or not, here are 94 songs that you might be gone, but aren’t truly forgotten. See if any were lost to you over the last 15(20)+ years.