This is a story about when Dr. Henry Eyring and Dr. Einstein were colleagues at Princeton University in the 1930's.
As they walked together, they noted an unusual plant (soybean) growing along a garden walk. Dr. Eyring asked Dr. Einstein if he knew what the plant was. (Dr. Eyring knew what the plant was and was merely toying with Einstein.)
Einstein did not know, and together they consulted a gardener. The gardener indicated the plant was soybean, and forever afterwards Eyring said Einstein didn't know beans.
from Reflections of a Scientist by Henry Eyring