Yes it is very difficult to sustain an unchanging love. I feel this is because of what we learn from the society in which we live, work, share. Until and unless we really understand from the inner mind that this life is for once only. The real and true love just depend on understanding, relations and material world. Hence it is very difficult to LEAVE it and hence we lose the unchanging LOVE. Real love is within. Hence, introspection of self is the key to LOVE SELF. The meditation preached by LORD BUDDHA through Vippashana and Mahayana Tantra iare unparalleled in the whole world. Hence all countries are looking to The LIGHT OF BUDDHA, the real India (not today's India known as Hindu). Even it has been proved that Jesus Christ visited twice and lived in India during his age between 13 to 30 year of his life and studied the very secret teaching of Lord Buddha, the Mahayana Tantra. There is a book in PALI language about 17 years of his studies of Lord Jesus in Ladhak and Tibet. He stayed in a cave known as HEMIS Cave in Ladhak. There is temple of Jesus Christ known as Hazarath Maulana Yusufa (Yesu) in a town known as KHANAMARI where he died near Shrinagar area in India. "The unknown life of Jesus Christ" a book written by Russian Traveler Nerowitch and Madam Lorrenja. This was published by Indo-American Book Co, Chicago in 1894, but it has been banned by Govt of USA.