Epimetheus was the brother of Prometheus. His wife was Pandora (Pandora's box), and Epimetheus was known to be impulsive and give no forethought to things, then begging his brother Prometheus, who was much more shrewd than him.
Good for a science-fiction novel, possibly, but a child with the name Epimetheus would have some troubles on the playground. Eppie could be an acceptable nickname, but it is more of a female nickname to me. Overall, it is a good name for a fictional character but not for a real person, no.
Epimetheus was the husband of Pandora in Greek mythology. His brother Prometheus stole fire from Zeus and gave it to man. As "punishment" to Man, Zeus created Pandora, the first woman, for Epimetheus. Prometheus' punishment was I daresay worse. He was strapped to a mountain top and visited by an eagle who ate his liver every day. Since Prometheus was a Titan and therefore practically immortal, his liver grew back every day, so the eagle had to come back, keeping Prometheus in constant agony.