I've been big into Eastern stuff like Hinduism, Taoism, Advaita, Zen, and Buddhism lately. I've also always been interested in science, and have developed a more recent interest in mathematics (but I slacked off in high school so I'm rusty on application). But the cross of those things is particularly fascinating to me. This is all gonna sound a bit disorganized, but oh well. I may organize it later.
In Taoism, you have yin and yang as opposites that describe reality. Yin is something still, existing in a manifested form, and yang is something moving, breaking from that form. Neither of these exist in any absolute sense (as in anything that can be called yang has yin properties and vice-versa), but they exist in a bunch of layers of nature. The opposites are interpenetrating and come together to create new things, which is part of the whole yin/yang thing. The coming together is the yin (manifestation), and the new forms are the yang (liberation).
Yin and yang is what you get by splitting reality in two to understand it. This is what happens when you make a concept of "reality" since the concept is separated from your experience of reality that you create the concepts from. Ever watch a movie long enough and get sucked into it, and then when it's over, it's like you're returning back to your life? It's like that. When you're caught in the movie and then finally start to separate observer from movie, you're already creating yin and yang.
For instance, atoms have protons (yin) and electrons (yang). Protons are in the nucleus, and the electrons are pulled to them by opposite charge and fly around them. In physics, you have f = ma. Mass is yin, acceleration is yang.
I've also been reading about Mayan philosophy and they had a view of the universe that is similar, but a bit more nuanced. They saw reality as a creation process of loops creating new things through their repetition. You have the processes in your body, the earth going around the sun, breathing, basically everything is a loop.
Death in this process is necessary, because change is required for reality. You can't look at something and know it's real without a process of knowing occurring. So to prevent the universe from not existing by creating an eternal form that does not allow further existence, old things have to be destroyed. But since the universe is a constant creation process, the things that exist will resist death, and that creates evolution. Animals develop more survivability, longer lifespans, and greater propagation in their fight to survive against death and increase their life.
Humans in particular are a great example. In Mother Nature by Sarah Hrdy, which speculates about the nature of how human mothering evolved and shapes our species, it points out how hunter-gatherers will select which babies they will raise or abandon based on how strong their will to live is, which they say they can hear in their cry.
But anyways, we don't actually experience death. You can't experience not existing. And what we are is not dependent on our bodies, since all of us are different people and can read these words and get the same meaning out of them. It's not like all seven billion of us humans come from different universes with completely different physical laws. Water hydrates all of us, oxygen is needed for us to live, etc. The brain chemistry that makes me conscious makes everyone conscious, so there is no absolute "I." Of course, the bodies we have are unique, but the consciousness that gives them existence is in all people. And that's how connection happens. We literally absorb the world and create an impression of it within our minds and share it with each other so we can vicariously enjoy the different angles of this infinite mystery.
Anyways, joy is literally this creation process happening to us. Think of why it's more fun to listen to music than to look at a wall. Music has more stuff going on in it. The universe makes more stuff naturally, since it started with hydrogen and here we are.
And the whole process is love. Not in the way we may think as some kind of ooey-gooey romantic stuff, but as in the joy of beholding reality and our desire to experience. But the whole opposites coming together thing is sexual attraction. Sexual attraction pulls opposites together for the continuity of new existence.
Pain is dissonance, basically. The reason it hurts to be burned is because our biological activity goes towards a state of equilibrium that being burned disrupts. A less abstract example would be someone says they'll give you your favorite food for free and you get excited and just want to sink your teeth into it but then they give you a bunch of styrofoam and tell you to eat it.
Anyways, I'm starting to think mathematics is a form of this recursive (not sure if I'm using this word correctly) process of love. The number one is singular, but two is two of those put together as one. Two is a singular concept of multiple things in one. Just like the universe splits things apart and brings them together in more complex forms (like how an atom is made of subatomic particles, and molecules are made of atoms). And mathematics is so precise because it is literally at the core of the metaphysical nature of our reality. But it is not complete and consistent at the same time (according to Godel's Incompleteness Theorem) because reality is not complete and consistent at the same time. Everything is moving, and any captured picture that can be known and understood is going to at least be slightly off from the movement. Like if you're going down a waterslide and taking a picture, you move by the time you can look at the picture.
It's like the observer principle. You can't know the position and momentum of a particle with exact certainty at the same time because position and momentum are different things. Position has no momentum, and momentum is leaving the position. Yin and yang again.