i think i felt the same feeling dido is singing about. if i get it right it is too much to handle the love for the man and the fear of losing him. therefore it's easier to pretend that you don't believe in love at all... you are just enjoying your time with someone, not attaching yourself to him - just not to make it hard to end. protecting yourself not to get hurt in the end, because you're pretty sure it has to be ended no matter when. But when it comes to end you don't want to feel that unbearable pain it causes.
its just self-soul-protection
i think i felt the same feeling dido is singing about. if i get it right it is too much to handle the love for the man and the fear of losing him. therefore it's easier to pretend that you don't believe in love at all... you are just enjoying your time with someone, not attaching yourself to him - just not to make it hard to end. protecting yourself not to get hurt in the end, because you're pretty sure it has to be ended no matter when. But when it comes to end you don't want to feel that unbearable pain it causes. its just self-soul-protection