Legend has it, coffee was discovered by an Ethiopian goat herder named Kaldi. One day, he noticed his goats frolicking around in an unusually spirited manner. He observed that they were also eating the berries of a nearby shrub.
Not being one to be left out of all the fun, he decided to try the berries himself. He was energized and pleased with the effects the cherries had on him. He told his friends and soon word spread throughout the region. The rest is history.
(Adapted from 2basnob)