Hmm. I think what the song is about is. The guy has done something wrong by her, (I lost my way, she said she'd stay). Even though the girl said they'd get through it, he can feel that they will never again get the amount of trust back into the relationship which took them years to build. So he tries to break through that barrier, but it is too strong for him. She has put up a wall to stop herself from getting hurt again, and after trying, trying and more trying, he realizes that, even though he still loves her immensley, he will never be able to break that barrier, never be able to rebuild what was lost! Once you do that to someone. You can't just hit restart, the barrier will be perminant. That's what I think anyways!