Zeus was not big on forgiving. He was the chief god on Mount Olympus, and what he said went. When the other gods and goddesses obeyed, fine. When they disobeyed, he threw thunderbolts around and thought up some very nasty punishments.
You might guess that the other gods and goddesses, knowing this, would stay out of trouble. Often they did, but not always. One example is the case of Prometheus.
Prometheus was a minor god who had a big job that Zeus had given him—creating humans to live on the earth while his brother, Epimetheus, created other forms of life. Prometheus did fine work, making humans in the image of the gods, but he took too long. By the time he finished, Epimetheus had already passed out most of the gifts that Zeus had given them both to share with all living beings. So animals had more physical skills, like jumping, running, and smelling, than people did. Some also had wonderful fur coats to keep them warm during the winter when people were shivering in their thin skins.
This bothered Prometheus. He felt sorry for the people and wanted them at least to have the gift of fire to help them through the long, cold nights. He asked Zeus for coals from the sacred hearth on Mount Olympus. "No," said Zeus. Fire was for gods and goddesses only; people should never have it.
Prometheus took it anyway. He snuck up to the top of Olympus, stole coals from the fire, and carried them down to earth and its people. Human life changed for the better. People were more comfortable and less afraid at night. Animals respected the fire and did not attack people who were near it.
Zeus was not pleased, but he held his temper because he saw that people were using some of their fire to prepare offerings of fresh meat for the gods. Then Prometheus went too far.
He noticed that people were working hard for their food, but they were burning the best of it for the gods. He showed them how to trick Zeus by offering him a choice of two gifts. One looked terrible but had the good meat in it. The other looked great but had only bones, gristle, and fat in it. Zeus chose the second, and when he realized what had happened, he was furious. Zeus sent thunderbolts flying around the sky, and he had Prometheus dragged to the top of the Caucasus Mountains and tied up in heavy, unbreakable chains.
As a god, Prometheus was immortal. He could not die, but he could suffer great pain, and he did. Every day an eagle flew down from the sky, tore out Prometheus's liver, and ate it. Every night the liver grew back, ready for the eagle's return in the morning for another meal. This continued for hundreds of years.
Zeus punished the people on earth another way. He gave them Pandora, along with a very special box—but that is another story.