Yes, a commonly occurring stumbling block for me is trying to use one language's syntax while actually programming in another, especially when it comes to all the Algol/C-like language, I probably mix things on a daily basis.

The concepts would be easier to grok up front if they just used normal function calls instead of "And now for this special syntax that only exists for this particular feature" which just adds more things to remember, instead of just the concepts themselves.