I always thought I knew a lot about teaching and learning because I was so good at it. At learning. And so I started teaching, and it turned out that I did know a lot about teaching, but it was all intuition. When kids start my physics classes I tell them that they already know physics intuitively: they can throw a ball up, predict where it will come down and catch it; they can stack blocks into a tower that won't fall over; they can push a swing and time their pushes so that the swing will go higher and higher.
It wasn't until I started my MEd program through the University of Oklahoma that my understanding of teaching and learning was smashed, scattered about, then rebuilt into a solid framework, organized and able to expand far beyond where it had reached before. I learned to consider the relationship between teaching and learning, what it means to learn, how the brain processes and stores information, about the psychological and affective side of learning, about approaching my teaching scientifically and quantitatively, about the importance of reflection and inquiry, and so many more ideas on which I can hang new lines of inquiry and new practices.
And so I continue to learn, and continue to teach, and I think I have enough lines of inquiry to last me a good 30 years, enough to make a career out of this racket.