I like to describe it this way. Don't think of it as "dark matter." Think of it as "dark gravity." SOMETHING is out there acting like a gravitational force. SOMETHING out there is bending space in very predictable ways that we can measure, test, and make predictions about. We know what this "force" is NOT. It is not the normal matter that makes up the stuff you and I and the stars are made of. It is not clouds of gas and dust. IT is also very cold and does not interact with normal matter and light or if it does interact it does so very weakly.

And the kicker is that when you make an energy budget for the whole universe, this "dark gravity" makes up 4x more of the universe than the stuff that you and I are made of. And stuff that is unknown makes me excited to be alive. Maybe this will be the solution to every issue we face as a people. Maybe it will be something we cannot use and exploit. Maybe it will be unknown for dozens of generations until we get a mind and the tools needed to say "Oh, that is what this force is."

The fact that humanity found something out in the universe that is driving the researchers bonkers makes me excited for the future.