Don't understand a part of a sentence of a youtube trailer

Could someone help me please?

There is a movie-trailer on youtube called „Divided brain trailer“

The link is

Neuroscientist Michael Gazzaniga criticizes the approach of book-author Iain McGilchrist (author of a book about the two brain hemispheres, called „The Master and his Emissary“)

At 3:22 in the xoutube-trailer Mr. Gazzaniga says something like this: „I used to give a lecture ‚The left hemisphere. Don‘t leave home without it.“ And that sumarizes the importance, I saw. That‘s where the heavy-duty liffening (listening ?????) comes for our complex (????) of life. This book is taking a selected set of neurscience findings and trying to relate them to the clinical psychiatric experience. I‘m not comfortable with that!“

I don‘t understand what he says where I put the questionmarks. Could someone help me with that, please? Just write down what he says.