David Chalmers coined the phrase "the hard problem" of consciousness.

https://en.wikipedia.org/wiki/Hard_problem_of_consciousness

> why do we experience anything?

Because the Essence that is the arrangement of molecules replicates onto other molecules, and it is more effective at replicating when it dedicates some of it's molecules to perceive and model it's own existence, in order to run experiments on it. That way it's more likely to find a behavior for the rest of the molecules to successfully replicate. So the molecules experience themselves, and the experience becomes more intense the more advanced the experiments are that can be run on the model.

The Hindu School of Philosophy named Samkhya/Sankhya gives you the appropriate Worldview in which your questions are answered - https://en.wikipedia.org/wiki/Samkhya

There is an "Objective Reality" (mutable, evolves into many forms and includes both material/non-material concepts) and a "Witness-Consciousness" (immutable and attributeless). The latter is embodied in one form of the former which we call Sentient Living Beings. But we forget the distinction between the two and experience reality through its own subjective evolutes within the embodied being i.e. Sensory Mind, Intelligence and Ego. Various techniques/practices have been prescribed in Samkhya/Yoga/etc. to break out of this illusion and realize that one is simply pure awareness/consciousness beyond any experience. This is what is called as Kaivalya/Moksa/Nirvana i.e. a state of mind in which there is total freedom from everything to do with objective reality.

See also the paper A landscape of consciousness: Toward a taxonomy of explanations and implications and previous discussion on it here - https://news.ycombinator.com/item?id=40844824

My adopted working hypothesis is that we have to simulate what others observe/think in order to predict their behaviour and then adjust our own expectations and plans. It's a lo-fi model, because we don't have access to their internal workings - and yet it's a powerful model because it needs to predict the behaviour of very complex agents. If we then turn that powerful machinery onto ourselves, we can add all the extra information we didn't have of others. So it's a much richer, more detailed description of what's going on.

It's not true that we have to be conscious - we can do things on autopilot too. The same way we can be thoughtless in treating others - we can turn the machinery off.

If you want to explore the future possibilities of that line of thought, then Greg Egan's Diaspora is good read.

The Minds That Left Reality | Diaspora

https://youtu.be/yYwqy4bzHG4

The two big problems: 1) Why is anything? and 2) Why am I here and you're over there?

Isn't that what death is? No experience whatsoever. Unless the universe ends up being a closed system and we have this discussion or slight variations infinitely many times.

There might be one like that out there but no one will know about it.

> Why can't I just shut off my experience and let my body do whatever it would do without having to put in effort

I do feel like most forms of leisure - watching / playing something, alcohol / drugs, sleeping - are basically this, you lose some of your consciousness and awareness in favor of what you're focusing on, or floating / free associating.

Friend, let me introduce you to the topics of philosophy, theology, and cosmology!

How would your body react to stimuli without experiencing it?

Are you thus postulating that the rock next to me is as conscious as I am?

That's a weird use of the term. Doesn't match how I would define it, but you do you.

How come you are assuming that there is an "end goal"?

Humans believing that they are special is as old as human history goes. Special as a species, but many groups also consider themselves special, and individuals as well. Seems to be an emergent thing from the human psyche. One that has had terrible consquences over the millenia, but I might be overlooking the upsides.