After the climax, the goal attainment, the reaching of the moment: There is a free fall of nowhere to get to next.
That is the dopamine draining out of our system.
Dopamine is the motivation and happy drug, and it does an unreasonable thing: It is present while we do not have what we want. And goes away the moment we get it.
It does another unreasonable thing: A sure way to increase the amount of dopamine, is to have greater uncertainty that we are going to reach that climax we seek.
And so, searching for an uncertain climax is our reasonable behaviour in this world.
And also, the cause of many, many of our problems.