Don't beat yourself over it. I read fast and need less sleep than most people. Plus the notion of history not being a slog through dates and unconnected remarks is so new to me that I'm going through this stuff on sheer novelty and enthusiasm alone.
I am also surprised by how much I'm enjoying reading this one. Usually, the audiobooks I read are 8-12 hours long and anything above that feels like a slog. I'm glad Judt writes as well as his phenomenal longread on Belgium that nobody read here: Postwar reminds me a lot of what a breeze Destiny Disrupted was, so if you haven't read that one I quite recommend it. It has a bit more name calling than Postwar but it also has a conversational tone throughout.
Destiny Disrupted is Fred McFriendly's Fun Facts about Founding Friendly Factions compared to Said's Orientalism. Ansary takes the viewpoint "man, you white people sure have fucked up Islamic history" while Said is basically "and you did it deliberately because you crackers be racist." The problem is Said nails it. You cannot get through that book without some deep introspection. I now feel guilty for liking Kipling.
For the geography majors, Orientalism is required reading. If I did more courses back then I would've already read it, but as of now it's on my reading list. By the by, would you recommend something like Zinn's A People's History to me? Is it comparable to Postwar? I dropped history halfway through high school so U.S. history was never covered. I'm not sure if Zinn it would be a good introduction.
Zinn is fast and easy reading. It will give you a perspective on US history that American kids don't get very often.