Say, a man is trying to find pleasure in doing something. he assumes he can have pleasure with playing, but just a while after start playing he feels definitely it can give him some pleasure. At that moment he stops playing and start finding for new form work/person/object/topic that can give him pleasure. It's not his/her fear to have the pleasure but it's like okay, anytime he can come back and have this any moment, a mean of it's in stock. But he never comes back until the feelings has been forgotten.
Is there a name of this type of disorder?