On March 13, 2007, I handed over the keys to my house, put my possessions in storage and headed out to travel around the world with nothing but a backpack, my laptop and a camera.

Three and a half years and 70 countries later, I've gotten the equivalent of a Ph.D in general knowledge about the people and places of Planet Earth.

Here are some of the things I've learned:

http://www.huffingtonpost.com/gary-arndt/20-thing-ive-learned-from_b_673264.html