He meets himself one day

He meets himself one day on the street, seemingly by accident. When he gets over the shock, and they are sitting down in a small cafe, he has several questions spring to mind.
"Are you a time traveler?", he asks himself.
"No. Not exactly.", his double says, a bit uncomfortably. "Today is not now. I am in the future, and this is an illusion. Like a memory projection, reconstructed from my past memories."
"What do you mean, exactly?", he responds.
"I guess I am like a memory tourist. This is a memory. You are a memory of me when I was a young man.", the double says and tries to smile.
"What's wrong?", he asks.
"I -- we are dying in the future. This is a sort a final trip down memory lane, literally.", says the double from the future.
"Oh.", he responds.
"I'm so sorry to put you through this.", says his double, "This was one of my favorite days in my - our entire life."
"What happens today that makes it so special?", he asks himself, feeling crushed and excited at once.
"Today you are going to meet the girl of your dreams. And she will love you for the rest of your life.", says his double, "Only this time you won't have to meet her by pure chance. I know where she is right now. Get up. My gift to you."
And later, his double said gently, "See there she is."
And he said, tears welling up in his eyes, "What should I do? How long will my life last? When you go will I go as well? What should I say to her?"
"You should meet her. I don't know. I don't know. I'll tell you exactly what to say.", His double replied.