I stumbled across "Eckhart Tolle" through YouTube recommendations - one of his Videos turned into an epiphany and it spiraled to binge watching most of his videos on his channel.
His content is highly relatable and looks fairly simple to implement., his technique - being PRESENT - being in the NOW, because that is all there is.
He gives great insight into being AWARE and CONCIOUS of your thoughts and choosing what to do with them - which is one of the more efficient ways - one could call it Meditation - to be in the NOW.
I wouldn't call this book "life changing" , I would call this - a realization of what you truly are.