You don't need to learn every feature to be competent in the language. Some features are advanced features that are not required in day-to-day programming (eg,

You don't need to learn every feature to be competent in the language. Some features are advanced features that are not required in day-to-day programming (eg, transients, you can go forever without ever touching them, but if you need performance they're there). A lot of the advanced things are of most interest to library authors.