Fantasy is pretty much a joy thief, taking one away from the gift of the present.
Our mind settles on something ahead, as though our happiness is a future tense.
You might ask, so I should not picture how my life should be in five years?
Well, please do. You definitely have to plan ahead. Discipline comes in here.
Like a fellow once said: discipline is when one's identity is so clear that they stop negotiating their feelings.