Hi! You come up with some great questions!!
For me, it was when I finished a project and wanted to go on to another one. My usual modus operandi is to learn the basics of a new skill, then move on to something new. Crochet, Tatting, Violin...oh, the list really goes on. With knitting, before I'm done with one project, I'm planning new ones. I don't know why it has been different for me than other things have, but there you have it. That was my "moment"