I love the name description you gave, this perfectly describes the categories I mentioned.
But I think it can get complicated sometimes when you know clearly that there's possibly something very important you could gain from the fellow but he is only interested in taking away from you.
it is very simple, if he is interested in learning from me, then he can only get anything from me if he is willingly to open up.
I think that's good. The willingness will judge.
QED! 👌👌