Because Jamaicans are known for having multiple jobs and Mexicans are known for working really hard....A Jamexican is a person that has a lot of jobs and works really hard at all of them.
Also known as "ethnically challeneged," people like this have 2 foot cocks, as well as foreheads that are beyond the norm, becoming "Five-Heads." Tendency to hate white folk, and make fun of any other ethnicity with disregard to his/her own real color.
One example is a Skinny Whiteboy who runs Cross country, others are not as well known, but tend to exhibit good grades and asshole-like personalities.
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.