Thoughts can create worlds. Every time you dream, you make worlds out of your own thoughts. You do not make dreamworlds out of atoms, out of “matter”. How many people grasp the significance of this fact? A dream, in and of itself, proves that a mind can create what convincingly passes as a material world, even though the dreamworld emphatically isn't material, but is made of thoughts produced by the mind of the dreamer.
Why don't we indulge in the boldest of thoughts? If one mind can build a dreamworld out of its own thoughts, what would happen if all minds dreamt together? What world might they create with their united effort, with their thoughts pulled together and operating as one? In fact, they would build the very world we are living in right now!
This is a universe of thought, and nothing but mind matters.