What a crazy thing to say. And, it was said by a brilliant, creative architect, Frank Lloyd Wright.
Why did he believe that? Could it be true?
Maybe, he proved it through his work.
It can be too glib to say, “Just because you believe it doesn’t make it so.” I agree. But, in your own life, those things that you really believe about yourself often do come true.
If you believe that you are a deeply happy soul, there is probably a good chance that state of bliss will arise. If you deeply believe you will succeed, I would bet you will, no matter what.
So, why not believe the best about yourself? There may be precious little else you can control in your life, but you have a good chance of controlling yourself.
Give it a try. I’m working on such things right now.