Clarissa Doesn't Explain It All Lyrics

Can anybody tell me what all of this is supposed to mean?
I know you never wanted anything but the best for me.
Can anybody explain who the hell I'm supposed to be?
Because waking up at four o'clock seems slightly unbecoming.
[ Lyrics from: http://www.cloverlyrics.com/e42452-rust_belt_lights~clarissa_doesnt_explain_it_all_lyrics.html ]
We're all floating gently downstream towards a waterfall.
Can we stay afloat? Sink or swim, either way we're going down.

This heaviness of heart is weighing down on me.
Maybe this is just an awakening.
This heaviness of heart...
Everything just falls apart.
Everything just crumbles.
Am I headed towards where I've already been?
Am I feeling comfortable in my own skin.
If history repeats itself, I'm living in the present.
If the past is just the future, guess I'd better learn my lesson.
Guess I'll always have a lot more questions than answers.
Can anybody explain anything?