No matter if it's a break, breakup, or even death. It will always end with a tear. Both of these times deal with a man wanting more than anything to be with the girl that he believes to be "The One".
After each break up with the two couples, the woman moves on faster than the man. It seems as if he is holding on to whatever he can to keep her close. For example, in I Want You, Costello says, "Did you mean to tell me but seem to forget", and then moves on to "Its knowing that he knows you now after only guessing, It's the thought of him undressing you or you undressing". These two lines show that she has moved on, and she never told him about it. The thought of her being intimate with another man, kills him! Seems like jealousy, but its more sadness. In "Thunder Road", Springsteen says, "Make crosses from your lovers, throw roses in the rain, Waste your summer praying in vain, For a savior to rise from these streets". These lines also show that after their relationship was over, she went out with other men, but no one ever was good enough. She was looking the "The One". Springsteen states that he isn't perfect, although, he can bring her happiness and get her out of the world that they are both in. Both songs resemble being broken up and wanting their significant other back. For Costello, it's his life; for Springsteen it's a plan for a new life.
Costello in my opinion brings the message of wanting her in a negative way. I state that because every other line is something that involves him getting hurt, sadness, or crying. Now, after hearing this song over and over, I began to really enjoy it. He says that she is the one for him, and he knows that he is the one for her, but she doesn't realize it yet. I believe that the only thing that Costello says positive is I Want You, and that what he says is true, not all the bull shit that other guys say. I feel sympathy for Costello, and you obviously can tell that he does and will do anything to get her back.