I am reading “Thinking, Fast and Slow” by Daniel Kahneman, and he suggests that happiness or a good mood might actually impair logic:

“…when in a good mood, people become more intuitive and more creative but also less vigilant and more prone to logical errors.” (p.68)

He provides other examples where even being forced to smile by holding a pencil horizontally in their mouth makes people more impressionable.

Increasing happiness too much arguably produces less dynamic cognition depending on your current balance of intuitive or logical thinking. Though people focused heavily on logic could probably benefit by being intuitive more often.

Self-actualization or fulfilling one’s potential, though more ambiguous, is a richer goal than happiness.