What does Daniel 4:33 mean?

Right then, everything happened just like the voice said. Nebuchadnezzar was driven away from people, ate grass like cattle, and his body got soaked with dew until his hair grew long like eagle feathers and his nails looked like bird claws. Daniel 4:33 - Modern Text Bible

(The prophecy is fulfilled immediately and literally; Nebuchadnezzar loses his sanity and lives like an animal.)