Based around Sam, and kinda his journey so far - don't know if it works, but here is the break down of the vid:
What happened to Mama Winchester and the parallel between Jess.
The guilt of losing Jess and how this may have festered some kind of hostility.
Ruby coming into the mix to mess with Sam's head, and Dean being between her and Sam.
Then about the other gifted kids, their abilities and their demise.
Followed with Sam at the end of S2, and the YED kinda messing further with Sam.
All the time being, Sam is going further to the dark side, while always having Dean at his side, and then facing losing Dean. The 'Don't act like I never told you' was in relation to Sammy and his 100%-ness.
And naturally, not all the lyrics make sense!
Hope you likey :)