Once upon a time, a famous zen master was enjoying yet another day of full enlightenment (nirvana) which included: baking chocolate chip cookies, oiling robots, and buying AA batteries at the local convenience store.
However, he'd forgotten to feed the dog that morning. His meditation remained unsettled, as on many other days (yet every day was different); a kind of rippling in the pond.
When he finally remembered his oversight, he wrote "suffering is an unfed dog" but in a fancy kind of calligraphy, such as would fetch a small sum at the local gift shop (tourists love this stuff).
Proceeds from the gift shop helped pay for dog food, as well as food for the monks.