There's the now famous anecdote that even Stroustrup rates himself a 7/10 at C++ proficiency. I've also worked on a handful of largeish (10k - 100k line) C++ p

There's the now famous anecdote that even Stroustrup rates himself a 7/10 at C++ proficiency. I've also worked on a handful of largeish (10k - 100k line) C++ projects both pre and post C++11, and also consider my C++ proficiency intermediate, even though I'm comfortable with the language and know how to fill in the gaps when I need to figure out something new, which now happens every 3 years. The language is enormous and complicated, and most people will forget how some of the rarer intricacies work if they don't use them frequently. And since most features are very useful in a few situations, but are not widely useful enough to change daily programming habits, this is basically guaranteed. The language is so big that intermediate is probably just the top of the scale now. Rust isn't that big yet (although it is getting more complex), but many more of the concepts in Rust are somewhat unique to the language, so you're not just learning new syntax. I think the "always intermediate / always still learning" feeling happens earlier with Rust than with C++ because of this.