Deirdre: Many philosophers have argued that the goal of every individual is to achieve happiness -- that is, the satisfaction derived from fully living up to one' s potential  They have also claimed that happiness is elusive and can be achieved only after years of sustained effort  But these philosophers have been unduly pessimistic, since they have clearly exaggerated the difficulty of being happy
Simply walking along the seashore on a sunny afternoon causes many people to experience feelings of happiness
It allows the key term happiness to shift in meaning illicitly in the course of the argument.