I haven't written a single zsh script (excluding one oh-my-zsh plugin) in my life, despite having used it on a number of systems in the past. I haven't written a single tcsh script in my life either, despite using FreeBSD on most of my servers.

In conclusion, it feels safe to assume that the shell language is entirely irrelevant for interactive use (yes, I know about the existence of the xonsh, thank you, Pythoneers). There's nothing to "learn" here, except maybe the "for ()" syntax. ;-)