What’s the largest, thickest, heaviest book you ever read? Was it because you had to? For pleasure? For school?

Hmmm... interesting questions.  The majority of books that I read are around 300-400 pages.  There are some that end up being upwards of 500 pages.  But for the truly long, I would have to go for The Historian by Elizabeth Kostova or something by Stephen King (like The Stand).  To be fair, neither of those authors are Tolstoy. They are a much lighter read.  So more than 1000 words doesn't actually seem that long.  I've been known to read a 300 book in a day, so pages alone don't really count.  I must take into account difficulty.  And all those crazy long books... my choice!