For years the people found themselves unable to ascend, until only a small group remained. Though they continued to meditate on their ultimate goal they were unable to ascend.
When Lt. Colonel John Sheppard accidentally crossed the barrier into the Cloister, he spent half a year with the inhabitants, protecting them from the Sanctuary Beast. Little did he realize this beast was actually their own fears being projected by their near-ascended powers. After they chose to face their fear and destroy the creature, every member of the village was able to ascend. (SGA: "Epiphany")