There's more to it than sensitivity to frequencies. It's also how easily can you pickup the difference in dynamics and I'm quite sure since other factors as well. A big part of mp3 compression mechanism is 'frequency masking'. I'm not aware of any studies on this, but I wouldn't be surprised if some people were more easily able to pick up artifacts after this, than others. I'm not the one to say whether some kind of talent is needed or if some form of training is sufficient. Some people can just sit down and tell the difference instantly. Others struggle, but I wouldn't worry about it. The most important bit is if you actually enjoy the music.