I am not much of a Rod Serling fan. However, I like this clip at Brain Pickings very much. In it Serling says that ideas come from "every human experience." He goes on to make the point that "the hardest thing on Earth" is to put ideas down. By which he means to do something with them.
Yes, getting from an idea to a completed piece of work is often brutal. To be honest, it's almost always brutal.