FLAC impresses me though- how do people even make a system like FLAC anyway
Honestly, all modern compression algorithms nowadays are extremely impressive, and some are very complex.
But, just as an example of how it can compress stuff so much, let's take this waveform/set of samples (the blue dots):

This is a stereo (2-channel) track. Now obviously the first thing you can do is see that the two tracks are very nearly identical; meaning at most you'd only have to store the differences between the first track and the second, which takes up much less space.
Then you can see that the waveform itself isn't totally random; there's a lot of structure to it. Like for a long while it's in the bottom half, then it moves up into the top half for a while, etc... You can store when the samples are in the top half and in the bottom half, and since there's a fair bit of structure there you can get good compression on that. Then you repeat, is it in the top or bottom quarter? You repeat this until it gets to a point where it gets so complex you can't compress it anymore. After all that is said and done, it's been compressed quite a bit!
You could also just store the difference between each sample (Which as you can see is usually quite small!), which wouldn't require as much storage space as storing the whole sample.
That does not rule out, however, the fact that I heard a difference when I was expecting none, so perhaps it's something to do with the effects/player/both? Something is handling the files slightly differently during the playing of the file. Perhaps there is an explanation for that? I'm open to discussion.
Alright. What music player do you use? Because for the one I use (Foobar2000), there's a plugin called ABX comparator:
http://www.foobar2000.org/components/view/foo_abxBasically, it's a double-blind listening test to see if you can audibly tell the difference between two audio files.
In fact, I'll provide you with two audio files here, one FLAC and one WAV.
https://mega.nz/#!Ct4WVJgK!YsDK6fOSs7EYyLU67vLIKxt7mz55f ihtUPf3NaXoNOo