Turned down the offer to be an instructor at work

Turned down the offer to be an instructor at work Today my boss asked if I would like to be an instructor at work. I turned down the offer and said that I still was inexperienced but in fact, it was my stutter. I guess people telling you that you can't speak etc etcetera has left deep roots. At the same time, I don't feel bad about it. I know my restrictions and I'm fine with it. In a better world, I would of course accept it but since that's not the case, what can I do? What do you think?