Why does Odysseus leave home?

In The Odyssey, Odysseus leaves home to fight in the Trojan War, and he stays away far longer because his journey back to Ithaca is blocked by danger, bad choices, and divine anger.

He is the king of Ithaca and has a wife and son, so leaving home costs him his household as well as his safety. The story begins 20 years after he first left for Troy and 10 years after he began trying to return. By then, Penelope is still waiting, Telemachus has grown up without his father, and the suitors have overrun Odysseus’s palace.

After Troy falls, Odysseus does want to go home. His strongest desire is to return to Ithaca, Penelope, and his family. When he later speaks of Calypso and Circe, both of whom try to keep him with them, he insists, “So nothing is as sweet as a man's own country.” That longing for home is what drives the whole poem.

His homecoming is delayed partly by his own pride and partly by the gods. The most important turning point comes when he blinds Polyphemus, the Cyclops, and then reveals his real name. Polyphemus calls on his father Poseidon to punish him, and Poseidon makes Odysseus’s voyage long and painful. His crew also makes disastrous mistakes, such as opening Aeolus’s bag of winds and later killing the Cattle of the Sun, which brings Zeus’s punishment.

Odysseus leaves Ithaca for war, then spends the rest of The Odyssey struggling to undo the consequences of that departure. The poem turns his original journey for glory into a series of painful lessons about homesickness, humility, and the fragile honor of a household left behind.