Oh I do it too -- I go to the library and sit down with a pile of books and sift through them to pick and choose which chapters apply to my life. Then, like you commented, I remind myself that "hey, I already know this on a basic level, guess I need the validation and a refresher b/c I did forget." It's very empowering to read.

I know my codependency will always be my achilles heel with narcissists and superficial people. There is no cure for mine bc its so deeply ingrained. But, I will give myself credit that now I trust myself more than I used to when it comes to recognizing patterns in other people that act as a warning sign, not to engage with them into a relationship or friendship.

Am I always correct with my intuition? No, but I'd rather trust myself first and then later admit I was wrong, then vice versa which is what I grew up doing: apologizing without processing the situation and my involvement first and what I contributed.

Some introspection is good, but too much then it becomes perseveration (aka "dwelling") and dwelling on the past is not helpful because we know we can't change our past.

I don't think you need to switch between healing yourself and staying informed on narcissism. You can do both concurrently.