Here's the way I see it. Everything is experienced in the mind. There is no difference between dream and reality. The only reason we call this world real is because it is recurring.
Let's assume, for the sake of argument, that every single night you dreamed of the same dream world. It had the same rules of physics and logic every night. It had the same characters every night. You perceived yourself as being the same person every night. And it seemed just as real as this world.
In such a case, how can you say it is any less real than this world? Every night when you go to sleep, you wake up in the same other world with the same sense of realism. You interact with the same characters, and you explore the world in the same way. You conduct your life in the same way you would any other recurring world (i.e. reality)
At what point would such a dream become more real to you than this world? And when it did, how would you tell the difference between the dream world and the real world?