It's a good question! This type of question (about the size of the universe and the speed of light) is one of the reasons why we developed a theory that the universe had a growth period we refer to as cosmic inflation.

In the very early universe, the universe expanded faster than the speed of light to become quite big. This doesn't break any laws of physics because space isn't a "thing" the way a photon or a calcium atom is a thing. It can expand faster than light moves. That is one of the reasons light speed is dwarfed by the size of the universe. The other reason, of course, is that the universe is very old. Billions of years is an amount of time our brains just don't comprehend.

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

That's an interesting interpretation. Genetics plays a role, but we don't know the specifics. We just know it's involved. Ergo, we don't really know why.

You've probably heard of "fight or flight response" at some point. Most animals have one. What it really refers to isn't just behavior, it's physiology.

Your body literally has systems dedicated to fight or flight response. In your brain, there are brain regions that activate in response to threat and get your body ready to survive. It's supposed to be functional: if you need to fight or run, you need adrenaline, focused attention, threat awareness, more blood to get to your muscles, and to know you're in danger.

Panic attack is when that response is triggered (where the idea of a trigger comes from) even though there isn't imminent danger from a third party perspective. Sometimes not even from your own perspective.

From the POV of your body, though, it's just trying to protect you. It has associated something with severe threat and it's responding appropriately.

There's a lot of things that can spontaneously kill anyone. Random blood clot in the wrong place, for example. And old age predisposes you to having those kinds of events and also not recovering from those kinds of events.

E.g., say an otherwise healthy person gets an active heart attack. Some people, for unknown reasons, their heart will try to power through the problem and keep pumping. It hurts and is not good obviously, but it could buy them time to get treatment. But strangely, some people's hearts will encounter this problem and just stop functioning. We don't really know why every time. It's partly genetic luck though.

Otherwise, death is usually from a chronic condition of some kind, not entirely unexpected. It's a process. You don't just die all at once. Your body exhausts itself slowly building from the primary chronic problem, like a bad liver. And it's in your sleep because eventually, your body doesn't have the resources to actually keep your brain fully conscious.

For example, my grandma was around for two weeks after we all agreed to stop the main healthcare and go for hospice instead. She was awake and "fine" in the beginning. no real bad pain or anything. You wouldn't know just from looking at her that she was dying. we could chat. But she no longer felt hunger and her body didn't really produce waste normally. as the time went on, she spent more time asleep. And eventually she didn't wake up much at all.