Every once in a while you get an idea that you feel will change the world because the idea is so great. Now, this might have worked in the time of ancient Greece or in early Rome. But today such an idea must be approached carefully.
Are you sure the idea really is that great? Have you tested it, through prototyping or discussion, against nay-sayers and won anyone over?
If not; shut up. The idea might not be that great...
If you have; That's great, now comes the real work.
Try to poke holes in your idea or theory until either: a-you succeed and the idea had some flaws, or b-you can't find any flaws and it really might change the world.
Just remember that most ideas that have changed the world (facebook, capitalism etc) have flaws, and many ideas that haven't changed the world don't have any real flaws.
The reason I'm getting into this is because I had an idea on the bus last week. An idea about what fun really is. A cognitive explanation to how fun works that is simple enough for designers to use as a road map in games development.
Now you understand my fear of hubris eh?
Over the next two weeks I will be fleshing out the idea and posting about it here, please, please, try to kill it. If we can't kill the idea together I'll just have to write a book about it.