Leaving the crowd behind, they took him along, just as he was, in the boat. There were also other boats with him. A furious squall came up, and the waves broke over the boat, so that it was nearly swamped. Jesus was in the stern, sleeping on a cushion. The disciples woke him and said to him, “Teacher, don’t you care if we drown?” (Mark 4:34-38)
Jesus suffered from the same exhaustion all humans face after a long day of work. What he did not suffer from was insomnia fueled by worry. Even while in the stern of a fishing boat in the midst of a furious squall, the Prince of Peace experienced peaceful sleep.