Everything we experience is only possible thanks to the brain. But we don't know how it converts the information it received into what we experience.
Thus our experiences, our existences, are nothing more that what we 'imagine'. We live inside our own world, we all live in a different world. Because we all experience the 'true' world differently.
Colors, smells, tastes, feels, thoughts, everything is nothing more that belief, belief what we make ourselves.
I live inside my own world of make belief. We all do in our worlds.