The happiness is more likely to spontaneously arise from the uncertain and unexpected. This can really surprise us and provide us with the highest and the longest lasting joy and happiness.
We try to understand the reasons and causes of our experience. Because we want to be able to influence the experience. Because we hope to repeat our experience. But familiarity makes us adapt to it. Once we have known or experienced something, we start adapting to it.
And once we start adapting to it, it’s causal efficacy reduces. It can’t make us that happy anymore. Seek out uncertainty, unexpected and unknown and increase the likelihood of becoming more happy!