"Too much of anything is bad, but too much of good whiskey is barely enough."
While that might be jarring to most people, there is a thing as "too much" optimism - or better put, irrational optimism. Such is evident in the current culture we live in where positivity is relentlessly championed as a commodity, and sold in a box with the perfect bow.
The problem, however, with this trend, is that it fails to acknowledge the existence of other emotions and the role they play towards a complete and richer human life.
Additionally, people are implicitly made to feel bad if they don't always feel good.
Pragmatically speaking, here are some suggestions to help you temper any kind of unhealthy happiness:
1) Don't keep score
"Count your blessing" is a truism that we're all familiar with and have heard either as a form of encouragement or reproach.
The crux of it being that if we take stock (which usually involves running through a mental or physical list) of all the good things that have happened to us, we should have no reason to feel sad.
While the intention behind this saying is well-meaning, the unforeseen effect is that we become predisposed to this thinking:
We need a long laundry list to be happy, and when we run out of things to add to that list, the likelihood of manufacturing happy experiences (to put on this list) becomes high.
With that said, don't keep a tally, rather, use whatever emotion (positive or negative) inform your decisions and behaviour.
2) Focus on vitality
As opposed to spending so much time on happiness, focus on things that make you come alive; by so doing you open yourself up to different range of emotions (fear, excitement, etc.).
Vitality affords you depth and helps you see your life in a pluralistic perspective.
3) Embrace negative thoughts
There are immense benefits for not ignoring negative feelings or thoughts - one, in particular, is the preparation aspect of it.
For example, when one considers the possibility of failure, the fear makes them prepare better and take extra precautions.
Individuals who undergo Neuro Linguistic Programming, are helped to understand themselves in a totality. This comprehension is one that is inclusive of all trigger points (the good, bad and ugly) and how best to navigate them so as to make better decisions.