How Charles Simeon was converted:

When [Charles] went up from Eton to King's College Cambridge in 1779, he was still a godless, worldly, and carefree youth. So he was shocked to be informed by the Provost within three days of his arrival that by an ancient college rule he was "absolutely required" to attend a terminal service of Holy Communion. "Conscience told me," he commented later, "that Satan was as fit to go there as I; and that if I must go, I must repent and turn to God, unless I chose to eat and drink to my own damnation." He had three weeks in which to prepare, and made himself "quite ill with reading, fasting and prayer." The Holy Spirit was also convicting him of sin. "So greatly was my mind oppressed with the weight of my former numberless iniquities," he said, "that I frequently looked on the dogs with envy" (Carus, p. 6).

From John Stott's introduction to Evangelical Preaching: An Anthology of Sermons by Charles Simeon, page xxviii.