The Christmas margarita and many margaritas have salt on the rim. One reason to add salt to the rim is because the salinity brightens the sweet and sour notes.
Questioning:
Since salinity can brighten the sweet flavor, can effort and pain brighten the happiness?
Associating:
When I look back to some past experiences, the outcome of the experience with more effort and pain can bring more happiness to me compared to other experiences where I had relatively fewer difficulties. It could be a good way to improve customer experience, by engaging customers in the product creation or design, letting them put some effort and pass through some difficulties, or doing some DIY to have a better experience.