Suddenly something happens that changes perspective and after them life is different. Incidents such as the assassination of Dr. Martin Luther King, the Challenger exploding after takeoff, the events of 9-11-2001 are collective experiences that changed the individual outlook of millions. For many it initiates a shift in thinking and an insight that forges change.
It happens with more personal events also. The moment when I knew my Jeep Wrangler was starting to rollover on a freeway froze time for me into an unspecified period of pure white until I consciously recognized I was on the side of a freeway staring up at a blaring sun with emergency personnel and bystanders surrounding me. It redefined my clarity of thinking to a new perspective in the days after causing me to start a long road of making changes in my life and ultimately thinking how to institute them permanently.
That is because changes keep coming and are reshaped resulting in life improving due to them. They never stop since you can make a list of things you want to accomplish or overcome but even when you reach a goal the next natural step is to keep going. Sometimes I think people are not successful at certain goals because they decide they're going to lose a certain amount of weight, work out to reach a certain look, read on a topic until they know what they want, learn to speak a language enough to be fluent and so on. After they reach their original goal they stop at that point rather than continuing and revising the goal to another level. Maintenance rarely succeeds at holding changes in place, except perhaps for short breaks to regroup, since it requires constantly raising the mark to keep it going. Maintenance really means continuously improving and learning.
My experience is life works that way. It took awhile for me to figure out the reason why I sometimes felt I hadn't accomplished arriving at a predetermined point was because I had reached and surpassed it but didn't recognize it since I kept on going. It is habit ingrained within me after learning from failure and a determination to figure out how not to lapse back into what I had decided to change. The pilgrimage doesn't end at the designated destination but progresses onward for a lifetime to keep learning and developing.