[ubercow13]

If you will fail an ABX test then you don't feel a difference due to an actual difference in quality almost by definition. Maybe you feel a difference because outside an ABX test you know when you are playing lossless files? That's fine but it's not the same thing.

[lisivka]

IMHO, lossy codec just removes some variation from music, so some nerves in ear are activated more often than other, so they are tired.