You don’t need to. Read up on the grammar if you encounter an odd construct or as a refresher, but remembering grammar rules is useless (And I say this as someone who can cite most of the grammar rules for English and German). It’s better to expose yourself to a lot of language and etch the patterns in your brain. In fact, I think not explaining grammar sparks curiosity, which is much better for remembering the rules you really need to know.