Same for me with computers. I was a programmer, a computer was simply a tool for me. Sure, I got to know a bit about them, and maybe more than many/most folk but that didn't qualify me as any kind of expert - and I was getting hardware & software questions, windows, peripherals.... I'd help IF I could but eventually denied all knowledge. It was easier that way.
Truth is, I should have been more confident in the first place and simply said 'no'. You want to help but sometimes just end up making life hard for yourself.