Making happiness your goal puts the focus on the end result and not on how most people end up actually being happy. Being engaged, excited, serene, accomplishing goals, having great relationships and similar things all tend to lead to happiness. Don’t put the cart before the horse. Focusing relentlessly on “being happy” is often missing the point. Focus instead on the actions and habits and experiences that bring happiness.
Remember that if you were always insanely happy, you would have nothing to compare happiness to, so it would simply become the “new normal” and not special at all. Happiness is really only experienced because you know what sadness and despair feel like. For this reason, many have figured out that a good default state is “equanimity.” You are not deliriously happy but experiencing more of a balanced middle area between happiness and just being mindful of your existence (but not sad). With balance you can enjoy the highs of happiness yet day-to-day you have the ability to stay untroubled and calm.