Elon may skim through some texts but he definitely also does some thorough reading and research as well..

"One bit of advice: it is important to view knowledge as sort of a semantic tree -- make sure you understand the fundamental principles, ie the trunk and big branches, before you get into the leaves/details or there is nothing for them to hang on to."

-Elon Musk Reddit AMA https://www.reddit.com/r/IAmA/comments/2rgsan/i_am_elon_musk...