When learning about classic utilitarianism (approximately, the quest to maximize everyone's expected well-being), I struggle because much of my well-being seems internal. If happiness or misery are significantly influenced by our internal processing of events, then how does this affect utilitarianism and its practical application?

I'll start with a few examples:

1. When I was a child, my family moved to a tropical country. I had some health problems due to the tropical climate. Fortunately, as an adult, I remember almost none of them, and instead have mostly positive memories about the time abroad. I occasionally remember them, which makes me feel happy.
2. I have been through some stressful times and depressive episodes in my life. This made me seek therapy and encouraged me to learn mindfulness techniques. Overall, these had positive effects on my life, and I now look back at the depressive episodes as challenges that made me grow stronger.
3. I have an app that I use to keep a mood diary. It has a "memories" feature that displays random entries from the past. I like this feature. Sometimes, it causes me to remember a past happy day, and I feel some new happiness as I think back.

In all these examples, the overall happiness derived from an event contains large contributions from internal processes: whether I remember the event in a positive or negative light, how often I think back to it, etc. This has a few implications for my behavior as an aspiring utilitarian:

It is difficult to base decisions on expected happiness. For example, was it a good decision for my parents to move abroad? If I were to have different memories from my time abroad, would this change the value of the decision? To estimate a decision's expected value, one would need to factor in unknowns such as the affected persons' happiness set-point, the parts they might remember (e.g., peak-end bias), or whether their diary app would randomly select the corresponding memory and show it again.

I recognize that these internal processes are second-order effects. To a first approximation, positive experiences will cause positive memories, and vice versa. However, my personal examples above show that this is not always the case. Are there situations where we should risk bad experiences, in the expectation that good may come from them?

Given that some of my well-being is internal, I wonder if I ought (in the ethical/utilitarian sense) to do more to improve these internal processes. Interventions like trying to increase my happiness set-point, doing cognitive behavioral therapy, reframing my memories of past events, cultivating gratitude, etc., might have a larger effect than I realize.

This is all still fairly unclear to me, so I decided to write it down, and would love to receive thoughts of the community. Some particular questions:

• How could I better understand well-being, hedonism, and related concepts?
• Am I overestimating these second-order effects of an experience on happiness?
• Have you ever tried to directly affect your internal happiness? How? With what result?
• (somewhat tangential) Do we know whether other sentient beings also have such strong internal processes, or whether this is a human thing? Does this affect how hedonists think about the welfare capacity of animals?