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.”

 

 

Moral: We can also learn from our mistakes.