QUOTE
and in LV's case, he chose to live his life without love
See, I'm still trying to get to grips with this, because we are not shown a single instance, in the book, where Voldemort made that decision. What we have seen is him being a horrible child, then a cruel teenager and an evil, twisted inhuman creature. But there is nothing in the text that suggests that he could have been anything different. We are expected to take for granted that he did make a choice.
And about Merope, I also find the suggestion that she chose to die equally problematic. Isn't it implied she died in child birth? In addition to that, although Dumbledore states that he believes Merope gave up magic, he also says:
"Of course, it is also possible that her unrequieted love and the attendant despair sapped her of her powers; that can happen."
If Merope was
unable to do magic, can the fact that she was unable to save herself really be held against her? A young woman, alone, pregnant, possibly full of guilt, resentment, who has no where to turn to except to an abusive family...
Isn't it notable that she went to the only possible place that could give her son a some type of home? Shouldn't it also be significant that she gave said son the name of the man she supposedly loved?
Merope made serious mistakes, and she is the perfect example of what an obsessive love can do. But I still think that taking Dumbledore's word at face value is dangerous.
Now about what Dumbledore meant, I think that "to love" is standing in for a number of different things. The word love, I think, is replacing a form of positive emotional conexion with others. Ultimately, we must feel pity for Voldemort, who never really connected with anyone in a significant way.
Sorry if this is confusing, I'm still trying to reconcile a few things in the books.