I have to reread books because I didn't get out in time to buy some new ones before the virus was upon us. The best bookstore in town used to be located just two blocks from my house and there was an English language bookstore just five or six blocks away but the first relocated and the second folded. By the time I got my wits about me, I didn't dare take public transportation to get to a bookstore.
So, I am rereading books that provide lots of opportunity for looking things up online. The first was 'Two Years Before the Mast' - I read up on brigs, how they were rigged and how they were sailed; early California ports and missions; Cape Horn, Isla Juan Fernández, Richard Henry Dana, etc. And now I'm rereading 'Wonderful Life' by Stephen Jay Gould and looking up all the "weird wonders" to see what has been written about them since they were discussed by Gould 30 years ago. Lots of changes, re-interpretations and new higher level taxonomy proposed.