I think Nickelback got the song idea from Def Leppard. I mean, there are variations to themes and words - but basically it's all about looking at an old image with a lusty, heavy heart. Yes, you can be lusty looking at photos of your childhood. It's all about perspective and wishing for something you no longer have such as youth or, you know, a supermodel.
Here is the evidence. Do you think Nickelback ripped off Def Leppard? Who has the better song?