I truly wish I were the sort of cultivated person able to take an interest in subjects as far removed from my own as cosmology and black holes. Sadly, I'm not.
However, as long as Hawking speaks of himself and his personal life I took a definite interest in this mémoir, which was globally a fascinating and easy read.
As regarding his studies, the one things I appreciated and/or actually understood (which I believe to be very much the same thing in this case) was the Grandfather Paradox (if you travel in time and kill your grandfather so you won't be born, then what?) and Hawkings's reason to why time travel most likely is and will remain impossible (because otherwise we'd already be flooded by tourists from the future).
Good one, and admirably concise!