Great Way to Learn Mixing

Now, I'm sure that this is not "kosher." But I stumbled upon one of the best learning experiences and interesting exercises I've ever had. While browsing about a torrent search, I noticed that you can actually find multitrack WAV bundles of some songs. Right now I'm playing with "Heard it Through the Grapevine"- it's actually just 8 mono tracks! I'm also gonna be playing with Stevie Wonder's "Superstition" when it's done.
Grapevine is really interesting because that great drum sound that I've always liked so much is so much different than I thought it was! Upon listening to it in isolation, it's really distorted. It's really interesting how much the recording carries the illusion of "stereo image" without actually being in stereo. I truly have no idea how you do that. I think that the sound I really like from these recordings is coming from lots and lots of instruments playing the same parts- and it really carries the effect I desire with or without panning. The whole mix is overdriven, but there doesn't really sound like there's a lot of EQ or compression- really any effects at all. This leads me to believe that these sessions really are as simple as they're fabled: nice hardware and no fuss. It sounds like these setups weren't tweaked to be exactly right, nothing was made perfect, tons and tons of noise and people talking in the background, etc.
It's an interesting experience and you should play with them if you are interested in recording or music.