Yes and no. Intellectually, I've come to enjoy absorbing enormous chunks of artistic or documentary expression in a single sitting. For instance, I count Reitz's Heimat I (15.5 hours), Kobayashi's The Human Condition (9.5 hours), Tarr's Sátántangó (7.5 hours), and Bondarchuk's War and Peace (7 hours) among my very favorite films, and have happily absorbed at least the latter two in a single sitting before. Same for music, I can take in an hour-long symphony or other musical work, no problem.
Reading seems to be a challenge at times, though. When I was kid, I could read for hours and hours without respite as easily as breathing. This despite having teachers and school principals certain that I had ADD. As I've gotten older, and this condition has remained untreated (for complicated reasons), it's become harder to "lock in" for very long during a session of reading, particularly for fiction. I've read 1,000+ page fiction works many times in my life (currently working on Rolland's Jean-Christophe), but it's been years since I've found this task remotely easy.
Non-fiction seems a bit easier, perhaps because I don't need to be quite as immersed in order to absorb what I need. Still, I have my struggles there too and I hope I can stick with my current read all the way through (which happens to be another massive tome). I have too many books in my ever-growing collection lying uncompleted.
One of these days, I really need to get this ADD treated. Sigh
Edit: Oh, another thing that's changed: as a kid, my ability to concentrate was so intense, I could block out the distraction of a tornado descending around me without breaking my focus. In fact, I used to much prefer playing or humming or whistling music while reading, as it only seemed to enhance my concentration. These days though, I get easily distracted by ambient noise, unfortunately. If I don't have a quiet environment in which to read, I cannot maintain for very long.
