By past and current experience, I'm pretty sure my future self isn't going to like me very much. I find it hard to justify doing something for some jerk that doesn't even like me, just because he might share some vestiges of my utility function and memories.

I'm guessing the reason I do anything with the future in mind is simply because that's how my 'utility function' was set up. I don't think there's anything irrational about that, though.