They are nothing but manifestations of the Self so that one’s parents are not outside the Self. So there is no reason to mourn.

Ramana Maharshi then read out from the Tamil version of Yoga Vasishta the story of Deerga Tapasi who had two sons, Punya and Papa. After the death of the parents the younger one mourned the loss and the elder  brother consoled him as follows: “Why do you mourn the loss of our parents? I shall tell you where they are; they are only within ourselves and are ourselves. For the life-current has passed through innumerable incarnations, births and deaths, pleasures and pains, etc., just as the water current in a river flows over rocks, pits, sands, elevations and depressions on its way, but still the current is unaffected. Again the pleasures and pains, births and deaths, are like undulations on the surface of seeming water in the mirage of the ego. The only reality is the Self from where the ego appears, and runs through thoughts which manifest themselves as the universe and in which the mothers and  fathers, friends and relatives appear and disappear. They are nothing but manifestations of the Self so that one’s parents are not outside the Self.  So there is no reason to mourn. Learn it, realise it and be happy.”