The refugee camps for Palestinians during and after the Israeli War for Independence were set up between 1948 and 1951.
This means that the youngest refugee is about 65 years old (in 2016). The life expectancy of Palestinians is around 72 years old.
Those younger than about 65 years old in these camps is a child, grandchild, or great-grandchild of the actual refugees, but not refugees themselves.
The youngest of the refugees have no or little memory of having lived in Palestine, unless one considers life in refugee camps as life in Palestine or Gaza.
I am not writing this glibly.
Almost everywhere else in the world, refugees have been resettled within a few years. In addition, they are rarely given political grounds for demanding a right to return to where they used to live. Some refugees do return, but this is rare.
When the Indian sub-continent was partitioned into separate Hindu and Muslim areas in 1947, becoming the nation states India and Pakistan:
The separation from Hindu-dominated areas granted to India was accompanied by widespread Hindu-Muslim rioting, the transfer of about 8,000,000 Hindus and Sikhs from Pakistan (especially from the Punjab) to India, and the forced relocation of about 6,000,000 Muslims from India to Pakistan. War erupted with India over Muslim dominated Jammu and Kashmir and ended in 1949 with a cease-fire line. . . .
(“Pakistan,” Grolier Encyclopedia of Knowledge. Danbury, Connecticut: Grolier, 1991. p. 193)
Note the words ‘forced relocation’ and ‘transfer’. Neither of these two words is used when describing the relationship between Israelis and Palestinians.
Of the roughly 14,000,000 people who were transferred or relocated between 1947 and 1949, the youngest are now about 67 years old (2016). The life expectancy in the region is around 60 years old.
The current cease-fire line in Kashmir is called a “line of control.” India and Pakistan have fought a couple of wars since the first cease-fire. China, for its part, invaded India and took over the region of Kashmir to the east of the Karakoram Range in 1962.
The United Nations makes decisions from majority, political considerations. The United Nations defines a refugee from Palestine as “persons whose normal place of residence was Palestine during the period 1 June 1946 to 15 May 1948, and who lost both home and means of livelihood as a result of the 1948 conflict.” The descendants of Palestine refugee males, including legally adopted children, are also eligible for registration.
When the UN Agency – the United Nations Relief and Works Agency for Palestine Refugees (UNRWA) – began operations in 1950, it was responding to the needs of about 750,000 Palestine refugees. Today, some 5 million Palestine refugees are eligible for UNRWA services. (“Who We Are – UNRWA“, retrieved May 9, 2016)