I think the difference though is C is not unlike most procedural programming languages. The main thing I imagine is coming back up to speed w/ stdlib and having to get back into the rhythm of managing memory. Regex is unlike anything you typically do on a day-to-day basis. It's just an alien mental model and once you get past the basics feels like you've acquired some sort of superpower few actually need.

It's like being a native English speaker who also speaks a few other latin based languages vs. having that one eastern language thrown into the mix.