Lyric discussion by tha1154688 

Cover art for Cardinals  lyrics by Wonder Years, The

The singer seems to be talking about someone he has known for a long time. Since at least seven years old. Either an actual brother or a friend close enough to be considered one.

"Cardinal crashed into my window... on the glass was a better life" His friend tried to get close to him, maybe hang out a lot, stay the night all the time, etc. because he had a shit life and saw that the singer's life was better than his.

"Staring at a hole in your chest that's been dug there for decades. American broken promises." - The American dream to live in a nice house with a happy family etc. is not the life his friend was living.

"Caught between the lies you've been fed and a war with your bloodstream."- Either talking about family that is cruel to him and has been lying to him or possibly the lying family as well as drugs.

"I had that nightmare again - you're seven and helpless, Angry as hell and you balled up your fists. But I laughed at your swings and I beat you half-conscious. I know that I failed you. Woke up in a sweat." - Might be dreaming about an actual event or metaphorically speaking to the fact that his friend was clearly angry and hurting, seeking help and he ignored him and all it did was make things worse "laughed at your swings and I beat you half conscious"

Boog

My Interpretation