There is a general idea that the simple fact of achieving your goals automatically lead to happiness, also that the failure to achieve your goals instantly make you unhappy.
I agree that achieving what you want bring you joy, fulfillment and happiness, but it is for a short time. It isn’t long-term happiness.
Also, I agree that the failure to achieve what you want make you sad or unhappy, but is also for a short time.
All these situations depend on your style of perceiving and interpreting what happens in your life. Many times we lack a “panoramic view” over our life.
Why achieving goals doesn’t ensure long-term happiness? Because:
1. Once we made or acquired what we wanted, our joy and happiness doesn’t last because we humans immediately get used to what we made or acquired.
2. This situation even may lead you to boredom and urge you to seek for something new to do or acquire.
3. Sometimes we even don’t stop to enjoy what we have done or have acquired, because we think this is something normal and automatically focus our mind on the next goal.
In this way we bounce from achieving one goal to another one without taking time to enjoy our achievements.