Why is he insecure?
In general, everyone is normally insecure in one way or another, and some people show it more than others. If the guy is insecure about something specific than maybe it's a touchy area for him. It just depends
Most girls are not insecure. They might seem insecure whenever you see them at school or someplace else but they probably have someplace where they are secure. For example maybe they're insecure at school because no one plays with her but maybe at the soccer field she's the best on the team and has a lot of fun. Just try and get to know the girl a little better.
The C language is not insecure. It is the programmer that is insecure. If we write programs that do not check bounds, or do not comply with specified language specifications, or do things contrary to the published library functionality, or do other "stupid" things, then it is our fault, and not the fault of the language.