That's where you need to implement your ideas and see what works and what doesn't. If you are the type of person that needs to know the truth and can't cover it

That's where you need to implement your ideas and see what works and what doesn't. If you are the type of person that needs to know the truth and can't cover it up and hide from it then your imagination will eventually adjust to reality (as long as you are getting good feedback). For me, I like the example of creating music, or even coming up with jokes. If you only imagine music or jokes you will never know if they are good or bad and you will just keep getting more imaginative but in an unrealistic way. As soon as you actually write that song, and tell that joke then you get actual feedback. It's the feedback that you need to calibrate your imagination.