User blog comment:PlantyThePottedPlant/Random Topic Blogging II: Electric Blogaloo/@comment-3006892-20120624210651/@comment-4005481-20120624233239

That doesn't make it any less original. You didn't know it existed until now, correct? Then you came up with the idea in your head on your own!

Plus, you have the challenge of making your story differently than Heinlein's, which makes it even more original,