Have you ever met a "Pot-Zombie"?

My uncle and several other folks I know who regularly smoke marijuana, and have been for YEARS, have a certain attitude and lifestyle that I feel is directly caused by marijuana. For example, my uncle has no desire to move up higher in his mechanic job. He speaks in a dazed monotone, is always wearing dirty clothes, eats the same thing every day, and ignores his children he lost in a custody hearing. A few other people also mimic this pattern that I know. All of them have no ambitions to succeed, and are incapable of intelligent conversation...so, have you guys met people like this?