“For the animal to be happy it is enough that this moment be enjoyable. But man is hardly satisfied with this at all. He is much more concerned to have enjoyable memories and expectations, especially the latter. With these assured, he can put up with an extremely miserable present. Without this assurance, he can be extremely miserable in the midst of immediate physical pleasure.”
— Alan Watts 
Agreed, but it sounds like you are phrasing it in negative context.
My take is that man has more mental capacity to see into the future than an animal and therefore he has to make opportunity cost choices with the currency being time and self. This is why we value the "expectation" more than the present situation, it is the return on investment from our choices. The ultimate goal isn't about being happy but about growth and developing the self.
The highest reward for a man's toil is not what he gets for it, but what he becomes by it. - John Ruskin
Agree.
Elsewhere, Alan notes that man cannot be more sensitive to pleasure without also being more sensitive to pain.
There is both a positive and a negative element, quite right.
