Hey Raaj, yeah I love that book but like everything… context is key. I for one don’t think the mirror thing is too healthy. And if you are coming from a place of lack, then affirmations might well do what Mark says. But the fact is that science (or Mark) don’t know for sure. Emotions do travel through language — that we do know — so in that sense, affirmations work, but it certainly depends on where you’re coming from.
Sorry for the political (ish) answer but life is grey and context is key, so nothing is ever really straight forward!