Are you real? You may seem real and solid, but you are mostly made of empty space. To demonstrate it, someone enlarged an electron to the size of one pixel, proportionally showing its distance from a equally scaled proton.
Click image above to zoom in
This is all basic stuff to anyone who's taken a physics class, but a lot of you have not, so I've made this graphic to show the distance between the two elements. You can click to zoom, but the electron is still invisible. To see it in all its scary glory, go to the page and scroll all the way to the left. As the page says: "We are all phantoms."
It's a good thing various fields take care of the whole empty space bit, or else we'd just pass through each other. [Phrenopolis]