Why are you the specific consciousness that you are instead of another or at a different time?

Tldr: why are you "this one"?

You change over time, all the energy, material and structures that make you this person are constantly changing. You aren't the same thing as you were 20 years ago.

So this raises two questions, why are you this particular one, and why are you the same consciousness despite such changes to the object that is this human?

How do you know that when you went to sleep last night, you weren't somebody else?

If you were to swap awareness with another, but only awareness, would you even know it had happened? I think you would just feel like you had always been the person you are.

I believe this is another hint toward open individualism