I'm 30 and I have no difficulty reading long books, nor watching Bladerunner. Actually I prefer long, slow-paced movies, especially the kind Sergio Leone made. And I've been doing this computer business since at least the age of 11.
There's a risk of bias confirmation here. Seek and ye shall find: you look for what you agree with, and you'll find it. You need to look for counterexamples too.
Great so there are different kinds of people. You prefer slower pace, I need more ideas per absorbed data unit to keep being interested.
My expeiriences with computers started probably more or less as early as yours (although I can't with clear concience call them business) but It's not about computers. It's about internet content.
I was always impatient but I see my impatience significantly grown over the last few years as I read internet blogs and sites like digg, HN and similar. I reached the point when I can start reading Terry's Pratchett new book, stop after few pages and forget it for weeks or months.
Maybe you don't spend as much time reading internet as I do (I really can't imagine how could I read more of it) or it has less (or no) effect on you but that doesn't change the probability of such correlation occur at least for some people.
I've always blamed TV for the loss of attention span - passive consumption. The internet, usually, is (more) active consumption, although you can make the point that it delivers in small packets.
Might be symptomatic of life in general, as people put out less effort to do anything - serious reading, like serious anything, requires some effort.
Internet consumption isn't, at present, very active; it's voluminous. There's so ridiculously much to consume, I find I'm growing impatient merely because I must demand density to get through the mass. This is a problem for me, since I'm not convinced dense stuff sticks.
There's a risk of bias confirmation here. Seek and ye shall find: you look for what you agree with, and you'll find it. You need to look for counterexamples too.