Don't Give Up Your Day Job Meaning
(idiomatic, often humorous) Somewhat sarcastic but usually good-natured advice used to criticise a person's degree of talent (especially in music or other performing arts), implying that he or she could not make a living from it.
Example: 2006 July 3, Viv Bernstein, "Said Makes His Case for Success in Nascar," New York Times (retrieved 11 Oct 2015):
"I remember after the school was over," he said, "I went up to the instructor just completely wound up like: â€˜O.K. man, how do I do this and become a real racecar driver? I want to quit my job and do this.â€™ . . . And he goes: â€˜Other Sports Beckon. You suck. Don't give up your day job.â€™ "