Simple Plan - Welcome to My Life Lyrics Meaning
It's about a teenager who doesn't have anything and whose life is terrible. He's introducing you to his life - "Welcome to my life." - and how terrible it is.
He explains how he feels "Out of place" like he doesn't belong in this world and that no one around understands him. He wants to run away, he wants to be somebody else, he feels like he's always being pushed around, he's sick of feeling so alone - it's just basically everything he says in the song.
The teenager suffers from deep depression - as he explains in the song - and isn't one bit happy. He doesn't have anyone to save him, to help him, to be there for him, and he's all alone - which is something no one wants to be, ever.
He also says, "No, you don't know what it's like. Welcome to my life.", as in it's so bad that you don't know what he's going through and he's explaining to you how bad it is, and how he doesn't want to be there and how he wants to find something more - something else - before his life is over.
Bottom line, it's about a really depressed teenager who hates his life and who doesn't have anyone there that cares.