Are we talking sphere of influence here or some weird spiritual living in a different plane of existence sort of thing?
For the latter you can control how you perceive reality and go through life in a self delusion.
I have to disagree slightly. All innovators appear delusional to the rest of the world, until their mind creation becomes reality.
I believe in this: Attitude and approach is more important than anything. Whatever you think about, you bring about.
Everything you see around you, was once someone's thought. So everything was created twice. Once in someone's mind, and second time in our reality.
Now that said, yes, you can also be delusional, and "create your own reality" and be blissfully unaware of how wrong you are in the real world.
I think it is best to balance both worlds - let your imagination flow, but also be aware and mindful of others when integrating your imagination into the real world.