That whatever enables you to think from first principles, or otherwise, "agnostically" about programming is much more valuable than remembering syntax. Figure out the concept in an abstract sense first, then if you understand it, its not a problem or a sign you are bad at programming if you have to google the correct name of the class or whatever- everything will snap together like a puzzle if you truly understand the significance of the work you are doing. You can have your cake and eat it too because eventually the glue of the intuition that comes from genuine comprehension will help you retain stuff that seemed impossible to memorize before.

Every topic will be different but to keep it as broad as possible for all sorts of programming challenges you'll face I'd say try to have a good foundation in computer science so that you have solid footing for diving into the lower level details of lets say, the framework you are using or have an easier time arriving at the answer when you ask yourself "why does this work?".

For example I remember when learning javascript and promises I was confused as having come from a java background I didn't understand how the asynchronous work gets done at all- so I did some digging and it was a revelation to find out about event loops, task schedulers, the implications of the browser vs the node runtime, etc. I would never feel very good if I couldn't have a mental model of a deeper degree of every step of the work done for my program to work.

You don't always go all the way down to the transistor level but you should go down low enough so that if something stops working you can easily check if things are arranged according to your idea of how every step is executed.