Travel is the only thing that you buy that makes you richer is a slogan that I have found to be true. Although I saw this from a ad trying to sell tours, which is not the way I travel, I still have experienced being enriched by travel.
(I hate it when those rock and roll songs you thought spoke to you during one's youth are now background for selling stuff, worst case in point, the song "We Won't Get Fooled Again, by the Who, my favorite line in the song is "meet the new boss, same as the old boss".
An April 2006 editorial for Time magazine, referenced the song, calling it an "antiwar anthem" that "conveyed a sense of betrayal by the nation's leaders, who had led our country into a costly and unnecessary war in Vietnam.
"Won't Get Fooled Again" was featured in a commercial for a 2000 Nissan Maxima and parts of the song have been used to sell TV shows among other things.
photo note: not my photo (sigh...) this and other fotos of Oaxaca here