All my life since has been a learning experience. Now I want to pass on five lessons I have learned during 10 years as secretary general of the United Nations that I believe the community of nations needs to learn as it confronts the challenges of the 21st century.

These seem true but obvious, although history has borne out the cost of learning these lessons one at a time (and time and time, again).

Kofi Annan - What I've Learned