What? He gets freaky in some other books, but Stranger is pretty clean for a free love manifesto. Every character I can think of was a full grown adult, I don’t think there’s a single scene even euphemistically depicting an old man sleeping with a young girl. All the sex even referred to was between people of relatively close age.

Grok just means to understand/drink fully. You drink water, and it becomes a part of your body. You understand an idea, and it becomes part of your mind. It’s an efficient word to communicate “understanding something fully enough to functionally incorporate it into your worldview”. It’s not that intellectual.