The feelings of joy and sorrow do not exist from their own side. Although they exist as conceptual imputations, you cling to them as existing from their own side. Feelings do not exist by their own intrinsic nature; rather, they are identified on the basis of contributing circumstances.
"Therefore, this analysis is cultivated as an antidote for that [false conception of intrinsic existence]. The meditative absorption that arises from the field of discriminative investigation is the food of the contemplative."—Shantideva
Feelings do not truly exist; they are not found when sought through analysis; they do not exist independently, but exist by the power of convention. Thus, the means for overcoming the misconception of the true existence of feelings is meditation on their lack of such existence. This entails analyzing the mode of existence of feelings.
Such investigation is an aid to meditative absorption and leads to the integration of meditative quiescence and insight. That increases the physical vitality of the contemplative and enhances the power of his [or her] spiritual practice. Thus it is called the nourishment of the contemplative.
From Transcendent Wisdom, pages 72-73