External rewards are rewarding for internal reasons. Perhaps see what spaces open up when you ask yourself why those stimulating conversations are rewarding to you. Perhaps that is what you hunger for without knowing it implicitly. Personal growth occurs through our exchanges in the other precisely because they give us more material to work with in our own interiority essentially. The encounter with people or experiences that exceeed the framework of your understanding force you to generate new concepts (even if not textual, concepts essentially exist as amorphous editable packets of data), these concepts are then useable as you contemplate yourself or others or whatever.