I have the exact same thing happen to me. When I hear certain songs I'm in a totally different place; I'm back in a certain situation, place and time and back with old friends, relationships, etc.
I'm be a little embarrassed to list my songs
since not many people like the kind of music that I like. Most of my friends make fun of me but some like a few of the bands, groups, or singers that I like.
I'll think about some stories and list some. I listen to a lot of country music. I know that sounds weird being a vegan since most of them are cowboys but for some reason that is just the music I like for the most part. I also like rap (if you can't tell from my online rap battles) and listen to a wide variety of rappers from the 80's, 90's and some current guys.
For a while I was also into the Smashing Pumpkins, Metallica, and a few others, but I don't listen to them a whole lot now. I even got into the Pop stuff and still listen to it on occasion.
Some people would think I'm crazy if they knew which CDs were going in my CD player each week.
Please don't think less of me, but the CD I listened to the morning of my recent bodybuilding competition victory was actually NSYNC hahaha
But that was upbeat and got me pumped up and ready, so it worked. I also listen to Creed sometimes, and in the same week Snoop Dogg, Dr. Dre, Eminem, M.C. Hammer, and a variety of country music like Kenny Chesney and Rascal Flatts.
See, I told you it's weird. I have quite a diversity of interests in music and not many can tolorate some of the singers I listen to, but they all take me back somewhere and I use music to help motivate me, calm me down, inspire me, and to bring back memories of friends and good times.