Your Attention Please

It is often said that our collective attention spans are being diminished by the influx of advertising, 30 minutes television programs, hell 12 minute television program (yeah Aqua Teen). I've certainly held and voiced that opinion. Recently in a conversation I witnessed the length of Pirates of the Caribbean 3 came up. On one side, one who felt that the film was boring and too long, on the other, one who felt that the film was great and the other person simply couldn't handle a cinematic masterpiece of such girth. It got me to thinking, Pirates 3 is a dumb summer popcorn flick (see review below), and it runs an ass-numbing 2 hours 45 minutes. How can this be if we're so collectively ADD?

Here's an interesting comparison:
Pirates of the Caribbean: At World's End -- 165 minutes -- 2007
Citizen Kane -- 119 minutes -- 1941
Casablanca -- 102 minutes -- 1942
Wizard of Oz -- 108 minutes -- 1939

Here we have a dumb, summer, loud-explosions movie clocking in significantly longer than 3 films that rank in the top 10 of the "AFI 100", that is, the American Film Institute's top 100 films of all time. Maybe we're not becoming such sheep after all. Could this possibly be a "when I was a kid we used to walk up hill in the snow... both ways" perceptual bias? I'm starting to think so. What do you guys think?