Oh wow. This is so full of emotions... The ending is happy (or, at least, not sad), but it left me with tears in my eyes. I guess it's their pure love for each other filling me up, mixed with the bitter-sweetness of their growing old and senile - I mean, David summed it up perfectly, they are happy and together, that's what counts, but some of the scenes (the one where Severus is in the dungeons and in 1991 (kind of), or the one where he brews in the kitchen plus the way Harry deals with the situation) just broke my heart. But you managed to balance that perfectly, counteracting the sad parts with things that made me chuckle. Um, I guess what I want to say is: What a beautiful, heart-rendering story!