Actually, it's more like "all of me" is tired. As if I wasn't already tired enough, Quicksilver is an enormous book and an exhausting read - it's over 900 pages, hardcover, unusually small type for hardcover, and extremely dense. It's thick with ideas, with history, with names, even stylistically - parts of it are written as a play, as written correspondence between characters, journal entries, and of course the usual standard prose style. It's a volume of great volume, and while I enjoyed it, it's not a light read by any stretch of the imagination.
I'm not even going to begin to describe what it's about as there's just too much there; I can't even do justice to a description of who it's about, as there are multiple main characters that it follows, and over different times in their lives as well. All in all it probably jumps through nearly a dozen perspectives over its 900 pages, making it that much harder to follow.
I can't recommend this book to anyone - but I don't mean that in the standard way. If you're a Neal Stephenson fan, you'll pick it up anyways and make the judgment for yourself (and it'll probably be mostly positive, as mine is now that I'm done). If you aren't, though, you need to start elsewhere, this novel is a terrible place to start reading his works, if for no other reason than it's the first book he's written which refers back to an earlier work (Cryptonomicon). Still, I tend to be of the line of thought that anyone that actually reads his books in order will get hooked very quickly; I think when he's at his best he's one of the best writers out there, and there are moments (sometimes long moments) of brilliance in each of his novels.
*phew* I feel like I need to go back to sleep now. :P Alas, I must off, work awaits. Avaunt!