I gave the vampire’s fear of sunlight a physiological explanation that had to do with the physiological laws that govern a spirit world or a cosmology. The spirit that has taken them over and made them inhuman is too sensitive to sunlight. It can’t thrive in sunlight — it’s simply paralyzed by sunlight, and weakened — and it can’t enliven their flesh. Therefore, the flesh starts to burn, because the flesh is dead anyway. The dark gift of immortality has different effects on different people. That they respond in different ways. Some people are emboldened, and some people are weakened. Some people are crippled by it, and destroyed by it. Other people are made into monsters by it. But the fundamental thing that happens with Louis is that it doesn’t change him. He is a guilt-ridden adult, living in grief over his dead brother, and he becomes a guilt-ridden vampire, living in grief over the fact that he has to take life in order to live. Perhaps it’s a lesson to Lestat that the basic personality doesn’t always change.