If you give a person a raise, they may need to bump up their percentage of tax withholding. To offset the pain of higher taxes, the person may want to celebrate and spend the (net) raise on a vacation. The vacation may require some new clothes. The new clothes may require a bigger closet, and the person may start to feel their home is too small. A smaller home remedied by a bigger home and a bigger mortgage payment, the person may feel stressed about the salary that just got raised, and in the end feel actually less happy than they did before this all started.
There is a sense in which life just happens. But in another sense we give away much more agency than we think, because of a series of decisions we make with little to no intention or purpose, and then we chalk it up to “life just happens” as a way to hide from the root problem. The former is hard enough as it is, but the latter is largely avoidable. Avoid it!