But he had long been secretly fired with the glory of Hercules, whom he held in the highest esteem, listening with great attention to such as related his achievements, particularly to those that had seen him, conversed with him, and had been witnesses to his prowess. He was affected in the same manner as Themistocles afterwards was, when he declared that the trophies of Miltiades would not suffer him to sleep.

Plutarch, Life of Theseus