It wouldn't matter even if you remembered it, if it wasn't for PTSD. That and the waste of a day.
The last question is strange, it implies that the goal of life is to fill up a trophy cabinet with golden memories and then, I guess, relish them for eternity, rather than to do things.
A life where I remember good memories is worth a lot more to me than a life where I do great deeds while sleepwalking and have no memory of it. What's the point of doing something if you don't even know you did it?