So, for some people (I think I'm using 'some people' too much in this blog) free will is a very important thing. They feel that if everything is deterministic, then it's already decided what they are going to do, so they can't decide it themselves. It's like something is forcing them to do things, and they don't have a will of their own. So determinism is a bad thing, and free will should exist to make the human existence meaningful.

This is wrong.

We are a part of the universe, and the laws of physics affect us the same way they affect everything else. And if we ask why something happened, there are only two options: either it depends on something else (so it's deterministic) or it doesn't (so it's random). When we make a decision, we can take many things into account, but in any case, it depends on something, so it's deterministic. There can be also a small random factor due to quantum processes in our brains, but even if decision making is completely deterministic, and everything that happens in the future is already decided (more about that next week), then it's still our decision, and no one forces us to do anything. So the entire concept of free will is pointless, it's one of these things that make sense when you don't think about them, but when you do, it doesn't.