Managing my mind around my business.

I have struggled off and on with the same question. My husband and I own a successful small business that we started about 10 years ago and have grown it over the years but not as much as we could. It is a fuel business and very industrial, but we offer alternative fuel that is cleaner burning. I am not naturally interested in science and mechanics but I have been able to learn what I need to know to present it to customers and pursue the business. Have I mismanaged my mind in regards to not believing 100% in what we offer? Or is it possible that this particular business will never be interesting enough to me to massively succeed?