I think everyone here shares two things: bipolar disorder and trauma.

We all deal with our trauma differently of course. For example, I like the land of denial when I can live there.
Mari, your younger brother may be dealing with the past by living in the present, but I doubt he's forgotten about it if his anger is palpable. Or maybe that's just part of his personality? I don't know.

But like Bobby said it's important that we all try to find and focus on good memories. I don't think it matters what they are as long as you have them...

While finishing up the cooking for a holiday dinner in my family, whoever puts the rolls in the oven mentions my mother's recipe for making rolls, "cook 'til black." It's a good memory, funny, and it eases the pain of her absence. It works.