Reasons for keeping lossless audio

• maybe today, you, with current environment cannot hear the difference between 320kbps mp3 and wav.
  • What about tomorrow?
  • What about other people than you? (At least as DJ you should probably care about others)
  • What about a different environment, e.g. new speakers, headphones ...?
  • What about effects that one cannot hear, but are still there?