I think it means that they don't understand someone, and they want to because they love them, so they want to take them 'for themselves' so they can know them properly without anyone else to interrupt or to change how they find them. I can't explain what I mean properly, it's hard. But I always thought it was about being in love with someone who is a complete mystery to them, perhaps isn't someone they particularly like or respect, but want to.
I think it means that they don't understand someone, and they want to because they love them, so they want to take them 'for themselves' so they can know them properly without anyone else to interrupt or to change how they find them. I can't explain what I mean properly, it's hard. But I always thought it was about being in love with someone who is a complete mystery to them, perhaps isn't someone they particularly like or respect, but want to.