Teachers need to learn. Without taking formal training or education classes at least once a year, I think I would feel as if I'm losing touch with my profession.
Of course, I can't know that for sure, because I have never let that much time pass without learning in a structured context, either through courses at the American Management Association, where I am a resident course developer, through local universities or training institutes, or through online educational services that I mentioned in a previous post. So I take these courses to keep fresh in my mind what it feels like to be in the learner's seat and to be evaluated.
The course I just signed up for is Crafting an Effective Writer: Tools of the Trade, given by Coursera. It focuses on the parts of speech and requires writing assignments, peer participation in a bulletin board-type portal, and peer review of writing assignments.
Is it a waste of time to take a course whose content I already know? Absolutely not. I'll be looking for new viewpoints and approaches to the content.
Be on the lookout for free educational opportunities, which abound on the internet. Here's to your learning.