I’d like to learne this powerful software-but I have no immediate use for it. Is it something that you forget rapidly (if you don’t apply it immediately)? Plus, can you learn enough from the training modules? As i say, amazing stuff, but I HAVE no immediate use. I’d hate to take a course and wind up forgettinh everything.
Do you already know the basics of formal project management, and just need to learn the software? If that’s the case, and assuming you know the standard MS applications, I don’t think it’s too hard to learn. How much of that you retain for how long without using it is hard to say. But it will make it easier next time you have to relearn it.
If you don’t know formal project management (by that I mean tasks, deliverables, dependencies, critical path, lag, stuff like that) I would learn that before the software. To me, that is what is really amazing and because it is so conceptual it stays with you.