I work in the security industry. Quite a few folks in this industry will quit their job to just go learn. They then jump back into a job once they get the skills they wanted. They do it out of passion for the work. I've made a sustainable business model out of my work. I don't talk to that piece, but I try to reflect on why I (and my friends who take a hiatus) are more productive when we're free of a normal workplace.
On HN, we're well acquainted with the benefits of working on our own. In the security industry, this isn't a common mindset yet.