True. And another part of the theory is that as Harry goes through each stage he becomes closer to each person that represents it (eg. Sirius in OOTP and Dumbledore in HBP). Therefore in DH, Harry will become even closer to Hagrid (which makes sense seen as he has lost two of the most influential adult figures in his life). And therefore, the loss will be even harder to face. But this theory explains why Sirius and Dumbledore had to die (I know, I don't want to believe that part either). Harry had to move through the stages and become an independant adult. This is why I believe Dumbledore knew he had to die. Harry had to lose everyone who had protected him in order to become the protector (IYKWIM). But Hagrid!!!