Ah, Yes, Even Then Funny. Past happinesses, for me, while not indistinct in my memory, tend to take on a glow over time.
Past pain is quite the different story.
Ugly incidents retain shardlike clarity. The details never die. I suppose there's a biological basis for that, as if it matters. One could say that mammals are built to learn from pain, and any mammal that forgets any detail of what causes it pain is one stupid furball. One could say a lot of things.