It is simple, but not having had experience with source control is usually an indicator that the developer in question probably isn't very good.
And yes, I did basically just say that I'm probably not a very good developer. :)
And yes, I did basically just say that I'm probably not a very good developer. :)
Now if you are claiming 5+ years of professional experience and have never used a source control system that is likely to trigger a whole set of negative questions surrounding what kind of experience you actually have, but it isn't a deal breaker - just a warning sign.