One of the refreshing and at the same time shocking aspects of Latin American culture and Spanish is the use of adjectives as nouns to describe a person. More accurately, to call a person. This is only shocking to those, like me, who have been raised in a hypersensitive "politically correct" culture where certain words are better and more polite than others.
It is not uncommon to hear someone referred to here as "el gordo" (the fat guy) or "la negra" (the black girl). I imagine people in the northern half of the Americas clumsily tripping over themselves trying to point out "the big-boned gentleman" or "the woman of African ancestry," respectively. If they were to identify someone as "fat" they may get slapped or, at the very least, a disapproving look.
I've been called "gringo" and "mono" as proper nouns enough times that I really should capitalize them. My maid, I'm sure, thinks my name is "joven" (young) and once one of my students referred to me as "el rosadito" (the little pink guy).
With all the blunt name-calling, I've learned to not be offended by being called what I am. However, I was taken aback the other day in the grocery store when the checkout girl, who was all of 20 years old herself, called to get my attention (I was momentarily looking at something else - most likely a shiny object). "Chico!" she yelled. I looked up to find her looking at me. Chico? Really? "Joven," sure. "Muchacho," okay. But "chico"?
I always joke that I look the same age as my students. Maybe 15 years old is a little too generous. Is five better? I guess I'm just be thankful she didn't say "niño."