One of the most popular stories was that of Edison relating to his inability to invent the electric bulb. Most of his attempts to invent electric bulb resulted in failure. In fact, Thomas Edison tried two thousand different materials in search of a filament for the light bulb. When none worked satisfactorily, his assistant complained, “All our work is in vain. We have learned nothing.”
Edison replied very confidently, “Oh, we have come a long way and we have learned a lot. We know that there are two thousand elements which we cannot use to make a good light bulb.