There are several versions to this, here is the the most popular legend on how coffee was discovered in Ethiopia.
Like all legends begin..
One fine day, Kaldi, an Abyssinian goat herder from Kaffa, when herding his goats through a highland area near a monastery noticed that his herd of goats were behaving very strangely. They were jumping around in excitement, bleating loudly and dancing on their hind legs. Surprised & not able to contain his herd, he found that the source of their excitement was a small cluster of shrubs with bright red berries.
Curious he tried the berries himself. Like the goats, Kaldi felt the energizing effects of the red berries. Filling his pockets with the red berries, he rushed home to his wife for her to try it. Experiencing similar emotions, she advised him to go to the nearby monastery to share these "heaven sent" berries with the monks.
At the monastery, Kaldis red berries were greeted with disdain. One of the monks called Kaldis berries "the Devils work" and tossed it into a fire. The aroma of roasting beans was too good for the monks to resist, they decided to give this novelty a second chance. The monks removed the coffee from the fire, crushed them to put out the glowing embers and covered them with hot water in an ewer in order to preserve them (or so the story goes).
All the monks in the monastery smelled the aroma of the coffee and came to try it out. These monks found that coffee has uplifting effects that were beneficial in keeping them awake during their spiritual practice. They vowed that from then on they would drink this newfound beverage each day as an aid to their religious devotions.
The monks have spoken!