Did the 6-day war really happen?

I don't understand why the "Palestinians" continue to insist that the "occupied territories" which were seized by Israel during the 6-day war still belong to the "Palestinians". According to this article in the Jerusalem Post:

• Islamic Jihad and Al-Aksa Martyrs Brigade leaders in the West Bank have said they will unilaterally cease all attacks in Israel proper for a 60 day period until the Palestinian Authority's elections on January 9.

  Hamas has not joined in the Fatah-led ceasefire, said its spokesman Sami Zuhri Monday evening.

• The Islamic Jihad's Shura Council, essentially its decision making body, has been debating a declaration of ceasefire since former PA chairman Yasser Arafat took ill almost three weeks ago.

  The group, as well as the Aksa Martyrs Brigades, have vowed to continue fighting IDF troops within the West Bank and Gaza Strip. They consider both soldiers and settlers living in those territories as legitimate targets.

Let's see. These groups (Islamic Jihad, Al Aksa, Hamas) seem to be saying either the PLO elects another leader who agrees that Israel should be destroyed, or the groups will continue fighting anyway. And the UNSC continues to pass resolutions against Israel. Unbelievable.