When the time was right, I did get that promotion, to AD. In the interim, I had worked hard to learn about it, and having missed earlier opportunities, I wanted it more, which probably didn't hurt.
We try to believe that we are capable of anything, and perhaps we are. But, along with being capable, we also have to be ready--ready to handle new challenges, ready to make time where there isn't any, ready to take risks and take chances. All those years ago, it took me time to be ready. These days, I try to face each day ready, but I also try to understand that "not ready" the first time doesn't have to mean "not ready ever." So, I work, and I watch, and I avoid nailing my feet to the ground or my mind to just one thing. So that when the next opportunity comes along, there's a good chance I'll be ready.