First of all, happiness is not a synonym for pleasure. Happiness is a composite made of feelings driven by basic human needs.
Let’s see what we need, on the feelings side, not bodily functions.
1-To be accepted by others
We get a glimpse of ourselves and settle on how the world works through the eyes and the opinions of other people. That’s why mainstream is so strong, it’s the collective idea of how things are done in this world. In every interaction, we seek others’ to understand our reasoning and actions. This is so important that when it happens neurotransmitters responsible for euphoria are flushed between our neurons. When our views and ideas are not accepted, stress hormones like norepinephrine come into play triggering a fight or flight response. (Look for Athene’s Theory of Everything on Youtube to learn more on that fascinating fact)
2- To believe
This is scientifically proven. From the placebo effect to the existence of a supreme being, humans prefer to believe, than to remain skeptical. And those who claim skeptical on one thing, believe something else. Believing is what comes naturally in our cognitive process; from communicating with others to cause and effect. Belief go beyond religion, it’s the way our minds reason and think.
3- To own
Sharing is a word that doesn’t resonate well with humans. We have the need for ownership. Starting from material things like home, land, vehicles and reaching out to people where the definition of ownership translates in a different way, yet the behavioral response remains. Nobody would say they own their kids or their partner, yet nobody would share them with others.
4- To mate in love
Regardless the heap of complications it creates, intimate physical pleasure accompanied with mental excitation (aka. love) is a human need and those who choose celibacy, are missing out on a major chapter of the human life book. It’s like going to a restaurant known for their popular pasta dish and try every other meal but this one. Besides the taste you are missing out, you are also unable to truly understand the rest of the people since that dish is the main reason they’re at the restaurant in the first place.
5- To create
That can be from making burgers at your local diner to adjusting the Hubble telescope on a spacewalk. Creativity has no ranks and no effort in it. Its more of a state of being that is fulfilling and satisfying on a personal level.
Considering you are not ill and your bodily functions are covered (food, water, sleep), If you add the above fulfilled: BELIEF + POSSESSION + LOVE + ACCEPTANCE + CREATIVITY you get HAPPINESS
And since these are basic human needs, the derivative is also, you guessed it… a basic human need!
Free yourself from guilt and escape the loop of self-pity and despair cos simply enough, you NEED to be happy.