I've been wary of saying this publicly, but I think it's something I can't dance around anymore. So here it is:
I throw everything out at the end of each school year.
Actually, there are maybe half a dozen lesson that I'll keep from year to year- but I only keep the idea of the lesson, not the stuff attached to it.
I'm saying this for a simple reason: I've been bombarded for years with people trying to move stuff they've made from one format or platform to another, newer one. I usually try to help, and the efforts are usually messy and only partially successful. They always ask how I'm managing the transition, and I always say that I don't have the problem. I think they must assume that I have some secret method for reformatting my teaching resources, but the truth is more simple. I simply make new stuff, all the time.
I think it's because I bore so easily. I can't imagine re-using something I've already used. Or maybe it's because I believe that each year's students are fundamentally different than the last, and the things I'm using to teach should reflect that. Or it's that I believe that my job, as an educator, is partially to create content, and if I'm using content from years ago I'm shirking my duties.
Whatever it is, it keeps life good for me. I'm always solving new problems, always re-imagining how things should be presented, always looking for a better way. And I never have to deal with moving my stuff from one platform to another.