The REP's of Asimov

I have now read this book for the second time. A couple of months ago I had these three words running through my brain. Rational, emotional, parental. Over and over again. So I did what any rational person might do. I googled it. And came up with this scifi novel from over forty years ago. I thought, I have this book! A quick check of the shelf of paperbacks downstairs confirmed my suspicion. I don't remember precisely when I read it the first time, probably in my twenties. I do remember enjoying it, but this time around so many themes and ideas seemed so much more relevant. Parallel universes, unlimited energy without pollution, failed genetic engineering. One thing I found particularly amusing. The idea that a 48 year old person is practically geriatric. Yet he still captures the heart of a much younger woman. Oh, and how academic types vie for favors and must publish or perish. Yup. The more things change, the more they stay the same.