The History of Rasselas, Prince of Abyssinia by Samuel Johnson

On the next day, his old instructor, imagining that he had now made himself acquainted with his disease of mind, was in hope of curing it by counsel, and officiously sought an opportunity of conference, which the Prince, having long considered him as one whose intellects were exhausted, was not very willing to afford. "Why," said he, "does this man thus intrude upon me? Shall I never be suffered to forget these lectures, which pleased only while they were new, and to become new again must be forgotten? " He then walked into the wood, and composed himself to his usual meditations; when, before his thoughts had taken any settled form, he perceived his pursuer at his side, and was at first prompted by his impatience to go hastily away; but being unwilling to offend a man whom he had once reverenced and still loved, he invited him to sit down with him on the bank.

The old man, thus encouraged, began to lament the change which had been lately observed in the Prince, and to inquire why he so often retired from the pleasures of the palace to loneliness and silence. "I fly from pleasure," said the Prince, "because pleasure has ceased to please: I am lonely because I am miserable, and am unwilling to cloud with my presence the happiness of others."