Most people know far less about their cars than they should. The smart ones present it to someone qualified when said car starts making weird noises, but the rest just try to ignore it and hope for an outcome that doesn't involve calling the insurance company.
Even if you can't fix it yourself, having a general idea of what's going wrong should help you when you're talking to the mechanic. Not only will it be easier for said pro to diagnose, but if you don't sound clueless you're way less likely to get charged for a $1,699 fuel placement matrix that was failing. So please, pay attention to our Car to English Translator: 10 Awful Car Noises and What They Might Mean.