I did C afor over a decade, I was really good at it. I haven’t used it in a decade. But, I left it off of my resume after an experience I had 4 years ago. I was applying for a C#/JavaScript job that didn’t have one line of C in the codebase, but one of the interviewers started asking me trivia about C. I happened to remember it, I got the job, but I learned my lesson.