Each framework and plugin has their own documentation and structure that needs to be reviewed and retained. On top of this foundation of programming language and frameworks knowledge, there are other principles and methodologies to also keep in mind:
- architectural patterns e.g. REST
- programming principles e.g. DRY
- workflow methodologies e.g. Agile and Lean
- semantic & accessibility best practices
In this veritable acronym stew of programming & process, I wholeheartedly believe that there's no shame in looking it up. There's simply too much out there to interact with and utilize to be able to retain it all. Need to find a string in a string but don't recall which PHP string function to use, go ahead and check it out! I think it's far more important for us to grasp what these languages, frameworks, and plugins are capable of before we attempt to memorize all the available methods and their syntax. You could always look up how to write a jQuery selector for all
<input> elements with a name attribute starting with "quarterly" (it's [name ^="quarterly"] by the way), having the knowledge that such a selector is available is an excellent start.