What we're not told when we are growing up, is that happiness is relative, and we all eventually adapt to our external circumstances. Instead, we're taught about fairy tales and happy endings and when our lives don't actually happen this way, we feel terrible. Sometimes, life is full of suffering.
This contradicts the ideal; that with a certain lifestyle, special partner, or incredible achievement, we will feel happy. About half of our happiness is determined by genetics, the other half is determined by our behavior and only a small percentage is from our circumstances.
A famous study done in 1978 with lottery winners and paraplegic accident victims suggested that the thrill of winning the lottery wears off. We all have a happiness baseline and even the most positive events won't have the same positive impact over time. So, even after winning the lottery, these people got used to their new wealth and it no longer contributed as much to their happiness. Conversely, accident victims returned to the same happiness level as before their accidents when they adjusted to their circumstances.
"Eventually the emotional aftermath of wildly fantastic strokes of luck or devastatingly catastrophic calamities will essentially leave you just as happy as you ever were."
Despite this study being small and inconclusive, it does give us food for thought. Your attitude has a POWERFUL influence over your happiness. We often evaluate our life based on how closely it lines up to what we imagined instead of embracing and working through the emotions that come with it. We should accept that we need to continue making efforts to influence our happiness to feel happy but also know that experiencing negative emotions and not feeling happy, is very normal as well.