Why is it so hard to remember you've been happy before? It is as if when you're in a long stretch of unfair events happening in your life, you can’t seem to draw comfort from past memories of happiness. It appears as if the prior acquaintance of the feeling is not enough to re-enter the same state. Yet this doesn't seem to be true the other way around. We have the ability to draw contrast from our past to our current state of well being when we need to and in a way the knowledge that our present is much more fortunate than the latter contributes to that satisfaction.
Life would be much easier to tread if our past experiences can interfere with the present in a more vivid way. Because sometimes the experience of the lessons we learn don't have the same intensity in the present after the wound has healed. Like dried paint going dull after a while on the palette. The same goes for contentment—you feel joy in the moment but after the day tapers so does the lived happiness that came with it. I'm not saying that we don't possess the ability to feel some sort of gratitude that the moment happened in itself but we do lack the ability to feel the same as we did during that moment in time. Yes, we reminisce about the good old days and look back at them with elation but that is all we can do. Events only contribute to memories and memories to happiness but to draw happiness from events after the event is no more can't be done because it is impossible to recreate the same.
So what is the point of making memories if they are strings of events that only exist in our mind and ours alone? There is no proof of its existence unless experienced by another but most of the time people experience differences in preception—the same day might evoke different feelings, different emotions even when spent together. Arguably, civilizations from the start of history have documented their lives due to this fact of memories. Art and creation stemmed as means of preservation. In a way what good is the imagined scenery without it taking shape on canvas. If even something as imagination must be captured to have proof of existence so must the lived experiences of human life.
This leads to the corollary question of whether experiences hold meaning only if witnessed by another. "If a tree falls in a forest and no one is around to hear it, does it make a sound?" scientifically yes, the falling of trees causes vibrations that create the sound—a sound no one hears. If no one hears the sound there is no proof of occurrence other than the vague assumption of it happening. But who eventually deals with the consequences? Definitely not the person that hears the sound to tell the tale but of the tree that falls. So should individual experience have the same weight without observers? Yes, because the person of occurrence is the closest of any observer it might have. The mind observes the event that occurs to a person and makes sense of it—and in that alone, the experience justifies itself.
Perhaps the inability to retrieve happiness is a feature of how experience works. It is not meant to be stored or replayed but to be lived and witnessed by you alone in the moment.
You were there. That was always enough.