Well, if you want to really bring science into the picture, and examine reality at the deepest level that science can take us - here's a summary.
The entire universe is just mostly empty space, together with the same few kinds of subatomic particles rapidly blinking in and out of existence. Thus "you" are essentially the same as "cheddar cheese", or the "moon", and the "chair" that you are "sitting" on.
That isn't necessarily a very meaningful answer. But it
is the most accurate picture that science can currently give you.
