Both pleasure and enjoyment are seen as positive states of emotion. However pleasure can be obtained through physical means such as sleeping, eating or having sex. However enjoyment requires a physical state of pleasure as well as an investment of time. Pleasurable emotions come and go, whilst enjoyment usually involves the growth of oneself through achievement but not necessarily reward. If an individual only pursues positive emotions in the name of reward, whether it be tangible or excessive physical emotion, it is possible that that individual may not garner any enjoyment from said pursuits .
A prime example would be an individual pursuing positive emotions through the use of drugs or sex. Initially the individual may experience enjoyment through those pursuits, however eventually the level of enjoyment attained may recede as the individual finds themselves only pursuing the physical and biological rewards. The more a pleasurable past time is pursued the less fun may be had from it. Eventually even the most pleasurable of tasks become mundane in nature and the individual may require something new or a change, in order to attain the initial level of enjoyment .