trying to read Eckhart Tolle.... again

Lately I've been trying to read Eckhart Tolle again. I've tried, and failed, in the past. I find him so abstract, and at times obscure.... and perhaps just altogether too "out there" for this little scientific mind of mine. But he's just come out with "Oneness With All Life", which is a collection of paragraphs and main ideas from "A New Earth".... basically, a less daunting, simplified version.
So I'm giving him another go. So far I've made it to ch.2....

"The primary cause of unhappiness is never the situation but your thoughts about it"
                    ~ Eckhart Tolle, from Oneness With All Life