What is a great idea?

Great ideas usually seem to come about when you're not sitting down and thinking about it.  I know this firsthand.  I've had ideas come to me before, while I wasn't even thinking about any subject in particular. 

Most great inventions throughout history, were invented when the inventor wasn't searching for a great, creative idea at the time. 

But not all ideas which pop into our heads turn out to become great ones, though.  Sometimes, you might get inspiration for an idea which at the time, seems to be great, but later proves to be not so great.  And at other times, you might get an idea which, when acted upon, turns out to be twice as great. 

No, it is not always easy to know if an idea will become great, but a great idea nowadays creates energy. And if we focus the majority of that energy on ways to improve on the idea, we will soon be on our way to achieving something great.