What happens when you are so well read that the only way you will benefit from the conversation is if they are in an entirely different area, and one that you are currently upskilling on? That may sound arrogant, but imagine trying to have a quid pro quo conversation with a rails noob about rails, after many years of constant rails apps. It's a purely one way conversation, and the same thing applies to any field.
I think that is a good question, but I assume that as a rails noob you probably had some mentor(s?) who pointed you in the right direction when you did stupid noob stuff. (Even if you learn mostly through books and blogs like I do, your knowledge is still beholden to someone else's instruction).
Maybe the exchange is an understanding that when the person you are teaching is an expert, he will pass on the information to another person.
That is a higher level exchange than the quid pro quo exchange, as it is more of a communal sharing of intellectual resources. Sometimes there is information that is important above and beyond its utility to me. It is important for me to share it.
Which I suppose gives an insight into why I feel the way that I do about intellectual property. Yes, it is important that people are rewarded and compensated for their hard work and effort put into researching new things, but the real reason that you research and learn new things is so that you can pass it on.
We're social animals, and we shouldn't let go of that.
