Epicurus was born in 341 bce in the Athenian colony of Samos, an island in the Mediterranean Sea near present-day Turkey. He began practising philosophy early, at the age of either twelve or fourteen, according to different reports. This interest was apparently spurred because of contempt for his schoolteachers. He wanted to understand what Hesiod meant when he claimed in the Theogony that first of all Chaos came into being, and from Chaos sprang Earth, Eros, Darkness and Night. When they were unable to interpret these lines for him, he turned to philosophy.

Epicurus said he was self-taught, but this claim is usually not taken seriously. The details of his early philosophical education are unclear, but he is said to have studied with Pamphilus, a follower of Plato (c.429–347 bce), and (in a more reliable report) under Nausiphanes, a follower of Democritus (c.460–370 bce), one of the inventors of atomism.

Even in the sketchy story above, we can discern many of the formative influences on Epicureanism. One of the main themes of Epicurus' philosophy is its resolute stand against the sort of destructive and retrograde superstition represented by Hesiod's theogony. Hesiod begins with a mythological account of the spawning of the universe from Chaos, and ends up with the triumph of the Olympian deities over their Titanic forebears. And with their triumph, these jealous beings, with superhuman powers and subhuman characters, are free to use us as pawns in their petty squabbles.