The question isn't what would you gain if you thought differently, the question is what WILL you miss out on if you continue to think the same.
Having a closed mind is the most expensive thing you will own, as it WILL cost you a lot in missed opportunities and experiences that you have closed yourself off to.
The most valuable thing you can own is an open mind, because EVERYTHING is an opportunity, and you are willing to be open to experience anything.
So do you want to own an expensive mind that costs you a lot, or do you want to own a valuable mind that earns you everything you've ever wanted?