I don't know if it's just a theory or proven fact, but apparently people's heartbeats sync up to the music that they're listening to. I'm not well versed in country music, but I think generally the beats are slower in country music... so maybe you like it because you're a chill dude and you feel better if your heart is beating slower?
Oh the 3 you listed, the Post Malone one was definitely more my style and I'd say its tempo is a bit faster than the first 2. I'm more into Kaiser Chiefs (for example) who have no chill.
I've heard that too, a reason one should listen to calming music at bedtime.
As for county music, I guess I just like the stories they attach to it and feel it has more heart than a lot of the other stuff. Just a personal opinion though.
I listen to all sorts of music, not chill stuff included, and really enjoy having a broad musical interest. Learning to play the piano from a young age and parents that encouraged me to explore the world around me and everything it contains has helped me discover music I may not otherwise have found.
I was actually going to make that point too... the stories and feelings attached to music can be a big driver - so much of my musical tastes center around what was happening in my life around the time a particular song or style I was listening to. Music (and smells) can bring on such strong memories and feelings, it's pretty amazing the way the human mind works.
Indeed, that's one of the most amazing and enjoyable things about music. I know my life would be somewhat less than it is without music in it.
Just like we all know our lives would be somewhat less than they are without galenkp in it.