I'm sorry mate but that just isn't true
There's been a couple of times where I've had duplicate copies of sets and I've played one of them, only seen the track name and been like you know this feels a bit flat and then it turned out to be mp3 not flac (and this has never happened with flac). I also definitely notice this during general listening, like sometimes if I'm really tired I'll ONLY want to listen to flac and mp3s will just annoy me. Believe me I'd love it if there was no difference, but there is.