"Can someone explain to me what, exactly, we're celebrating?"
That a bunch of wealthy white farm owners and business owners who had an absurd amount of time to sit around and read got it into their head that taxes were too high and unfair, that they first wanted at least a seat in Parliament and then just decided they could govern themselves better at home, and broke with the fatherland in order to do so.
...I guess?
For all the rhetoric surrounding the day...it really wasn't about fanciful ideals of (to borrow from that "other" famous 18th century revolution) Liberty, Equality and Fraternity. Not at the start, anyway.
Or even that all men are created equal--not when the people calling the shots are wealthy male land owners and there are slaves being owned. (And besides, Locke had already both written and been a hypocrite on the equality/slavery issue a century before Jefferson.)
I don't know, maybe I'm not "patriotic enough," but I've honestly ceased to care about the 4th of July and a lot of the "ideals this country was founded on," as 1. More often than not those "ideals" weren't really there to begin with (see: equality) and 2. I just don't care that much for nationalism. I view America the same way I view Los Angeles County--
I like to take shots at them, say they suck, groan about them...but they're still where I live and they're still, relatively-speaking, one of the better places on Earth one could live, especially looking at all the problems in Africa, the Middle East, Asia and so on...
I dunno, I'm much more "Go Team English Language!" or "Go Team Western Culture!" than just "Go America!" (unless it's sports...then go Team America, kick ass...and go the UK/Israel if America is defeated.) ;)
For me, America's just one piece--albeit a sizable one--of a larger cultural sphere...and I think that's what matters more in a globalized world, or what's easier to connect to, anyway.
Cultural Spheres are the new Nation States. (Maybe not, but it sounded good and, um, freedom, and 'muricah, and all that.) :p