The informant is a nineteen-year old student born in Australia whos lived in Egypt for two years, England for two years, Jordan for four years, Egypt for two years, India for four years and currently resides in Los Angeles, CA for university. He is the son of an Egyptian ambassador and speaks Arabic, English and French. He shall be referred to as SH.
If your mothers a garlic and your fathers an onion, how could you smell good?
As SH explained, this proverb is delivered with a sarcastic, deadpan sense of humor he claims is very common of Egyptian culture. He explains that it refers to how if your fathers one way and your mothers the same way, a child can never expect to be any different. Thus, it addresses the anxiety of the example set by parents and how it can be difficult for a child to break away from that.
To me, the proverb suggests a certain amount of devotion to tradition in that culture. While in western culture we believe that a person can lift him or herself out of any circumstances, this seems to suggest that a person cannot escape his or her nature of birth if their parents nature is so set. As it is used negatively (with two smelly vegetables), one can imagine that it is used in a derisive manner. At the same time, the proverb addresses this in a lighthearted way, as if to encourage the person listening to embrace their identity no matter what it is, even if it does not seem desirable at first. Thus, there does not seem to be the same flexibility of identity as there is in Western culture.