Education and exposure to new ideas.
I attended IDEA conferences since 1995, at least one per year, often two. Initially, I was like a kid at a buffet, not exactly knowing that I liked out of all the choices. Even today, I enjoy going to classes I never experienced before, or listening to new subjects.
Getting a small bite of new stuff has often motivated me to dive into specific subjects in greater depth. It was the exposure to MELT in 2009 which has prompted me to pursue a MELT Instructor certification which has significantly transformed my training apporach.