I obviously don’t know the context of this quote, but are you sure you’re not misinterpreting the intent? It seems that you’re approaching it as talking about specific types of words or phrases that are “ropes” for the language, but I don’t feel like that was the intention.
Reading it, I think the person is describing how the loose, undefined “threads” that form in your mind from words and phrases you start to recognize gradually turn in to strong “ropes” (collections of threads, thicker and stronger) on which you can connect many more things. Anchors in the language, maybe? There wouldn’t be a set list of words. It’s what forms for you. I think this is what lollipophuho is talking about as well.
I could be mistaken. But I don’t really understand the idea of the former, and can definitely attest to the reality of the latter. With constant exposure, the things you are familiar with work as a base to allow you to grasp the things you’re not.
Last thing, I think watching shows with Japanese subtitles is great, if you can. It might feel like cheating your listening comprehension in a way, but I think it really helps to build these connections.