They could condense the whole series to 12 episodes....and it would all be meaningless.
Other than a stretch in Season 2 I've never been bothered by the pace. In fact, I actually kind of regret the non-stop short seasons because there is precious little character stuff. I'm not complaining, because the plot demands it, but LOST is just as much about the characters as the island. If you're watching it just for answers, you're watching the wrong show.
There are enough TV shows, like Heroes, that not only ask but REQUIRE that you turn your brain off. The makers of LOST are aiming for great television and more often than not achieving it.
Are you serious?
The character plots aren't that deep or complex, that's typical TV drama stuff. It's told out of order . . . is THAT the big brain-challenging aspect?
The "bigger" plot is the only thing that might be somewhat challenging to follow, but only if they didn't stretch 1 episode's worth of "bigger" plot information to be revealed over the span of 5 episodes at a time.
I guess it just goes to what kind of show you want. Personally I'm not all that interested in SO much backstory for every character, especially when characters get killed off before they're fully exploited anyway. Who cares about Shannon and Boon when a) they weren't that interesting to begin with, and b) they're dead now, so what did it matter to know about their history anyway? What, are they going to be brought back somehow in some preposterous plotline?
And the flashbacks/flashforwards are always really formulaic, and usually don't add much to the plot on the island their flashing from. Really the only thing that makes this show unique is the mysterious island stuff, and when the info revealed over 4 seasons can be summed up in a few paragraphs, I can't possibly see how that's challenging your brain, other than your patience.
And as someone who prefers Branagh's unabridged Hamlet to Mel Gibson's, you can't accuse me of short attention span.
Look, it's a pretty entertaining show, and obviously I don't hate it or I wouldn't have seen every episode, but The Wire this ain't.