Happiness is not an end destination, it is part of the process and journey. You can’t tell yourself that you will be happy if this thing happens, or if another thing happens to you. Happiness is about being happy with how you respond to things throughout the day. It is something you can choose to be or not be.
Regardless of what may be happening throughout your life, happiness is a choice, not an end of the destination kind of feeling.
I really like how simple, yet profound Buddha was with his outlook on happiness.