[slingblader]

I'd keep living, I'm sure it's what any one of them would want. But it'd definitely weigh on my mind a fair bit. I'd have to do something to formally acknowledge and honor them. Something they'd enjoy, but then I guess I'd let it go emotionally, and just remember them.
Paralyzed? I'd have to assume the same thing. None of them would really want to drag all of us down, I'm almost positive. Although, of 5 of my truly close friends, 4 would probably end up killing themselves trying to do something in their wheel chair lol.

Memory loss? Well, if they're fully functional, and can continue on no prob (which I assume you mean....) I guess I'd be making a "new" friend. Assuming the type of person they are is intact anyway, ignoring the idea that you are defined by your memories and experiences.