You´d be surprised how many physicists have never read Einstein in the original. I´m not a physicist, but it may be because Einstein´s theories were always evolving. Here for example, in his theory of General Relativity, I counted remarkably fewer equations than the same theory in his Wikipedia entry.
I read this in the most tranquil, serene library; it was just one long large glass window on a unspoiled grassy bay. So maybe that´s why it was so easy. Or maybe Mr. Hawking cut out all of the hairy detail. His footnote to the equations for gravity do damn with faint praise.
Einstein the younger was practically outraged at Newton´s view of gravity, but one General Relativity later and still no one really knows just what gravity is, in a universal sense.