One can think of light as a wave traveling through time and space.
Since light is an electromagnetic wave, it has both electric and magnetic components that are perpendicular to each other. If the electric component lies in one plane and the magnetic component in another, there are infinite possible ways they can be arranged in three dimensions. This is what we call unpolarized light. Most of the light we see around us is unpolarized.
But what if we somehow allow only one of these infinite ways in a light ray? That particular light ray is then called polarized. Thin sheets of plastic that allow us to do this are called polarizers.
Similar to polarized light, our memories are also polarized versions of reality. If we draw an analogy:
As we evolve and change as individuals, we keep stacking these polaroids on our memories. Depending upon the polaroid, we may or may not remember a memory fondly. If we are "happy," everything seems wonderful—even difficult memories seem worth it or become just humorous incidents. On the other hand, if we are "unhappy," everything seems gloomy, and we just want to revert to our previous "happy" states.
But just like a plastic polaroid sheet blocks light, our current and previous states also block the truth. As soon as the first polaroid is placed in front of memory, the truth is lost, and there's no way to get it back. Actually, most of the truth is lost, with only a fragment remaining. That's not to say it's an outright lie—it's just a memory, and that's all it is. And that is how we should observe it; we should not let this memory cloud our present.
Unlike memories, truth is always present in the present, if we choose to see it. We should cherish this. Truth is not easy, it's not hard—it's just truth, and it may not be for everyone.
The way we perceive our past is constantly changing as we grow. What once seemed like a devastating failure might later appear as a necessary stepping stone. A cherished memory might later reveal itself as something more complex when viewed through the lens of greater life experience.
This is why two people can experience the same event yet walk away with completely different memories. Their individual polaroids—their unique perspectives, past experiences, and current emotional states—filter the reality differently.
Perhaps the art of living well involves recognizing when we're viewing our memories through particularly distorted polaroids. When we're at our lowest, our memories might appear unnecessarily dark. When we're at our highest, we might romanticize difficult periods that shouldn't be repeated.
After all, not everyone can stare into the sun without polaroids.