Meditations 7.27

Think not so much of what thou hast not as of what thou hast: but of the things which thou hast select the best, and then reflect how eagerly they would have been sought, if thou hadst them not. At the same time, however, take care that thou dost not through being so pleased with them accustom thyself to overvalue them, so as to be disturbed if ever thou shouldst not have them.

Marcus Aurelius, Meditations 7.27, translated by George Long

Dream not of that which thou hast not as though already thine, but of what thou hast pick out the choicest blessings, and do not forget in respect of them how eagerly thou wouldst have coveted them, had they not been thine. Albeit beware that thou do not inure thyself, by reason of this thy delight in them, to prize them so highly as to be distressed if at any time they are lost to thee.

Marcus Aurelius, Meditations 7.27, translated by C. R. Haines