This can be observed on a biological level with our brain releasing dopamine (sensation of pleasure) whenever we attain something we want. However, once this feeling goes away, we require a new goal in order to attain another "fix". We truly are just dopamine-addicted creatures (notice how our phones and TikTok provide us with short bursts of pleasure).
It then makes sense that happiness is not something you achieve. It instead describes the process in which you attain your ambitions. You should strive to set these types of goals in which the process brings you joy and pleasure. This is also why striving for just money will never bring you joy, only the process by which you get there will bring you fulfillment.
My current goal is to bring our company into a breakeven point. What brings me immense joy is working with my team, interacting with customers, and fine-tuning our operations. Actually achieving our breakeven point will cause my brain to briefly experience a surge of dopamine that will quickly vanish, and my brain will await the next goal to set.