But they do create an image of the world, and they do live inside the image. So in a sense it is correct to say that we all inhabit a personal universe and reality is what our personal universes share in common.
I think you are confusing the power to create a mental representation of a reality with reality itself. It is a fact that we can and do create an image of the world in our minds. It's also a fact that the mind has limited powers to change the image of the world created by other minds - there are constraints known as the laws of physics. Last but not least, it's a fact that the real world only resembles the image created in our minds to the extent that the image is self-consistent.
That last assertion probably needs explaining, but the point I'm trying to make is that it's a fact that we all inhabit a personal version of reality.