It’s worth remembering, then, that we are not designed to be consistently happy. Instead, we are designed to survive and reproduce. These are difficult tasks, so we are meant to struggle and strive, seek gratification and safety, fight off threats and avoid pain. The model of competing emotions offered by coexisting pleasure and pain fits our reality much better than the unachievable bliss that the happiness industry is trying to sell us. In fact, pretending that any degree of pain is abnormal or pathological will only foster feelings of inadequacy and frustration.
Postulating that there is no such thing as happiness may appear to be a purely negative message, but the silver lining, the consolation, is the knowledge that dissatisfaction is not a personal failure. If you are unhappy at times, this is not a shortcoming that demands urgent repair, as the happiness gurus would have it. Far from it. This fluctuation is, in fact, what makes you human.