Jerry: “So that weird ‘wet rock smell,’ before it rains, is called ‘petrichor’ huh? Never knew that.”
RJ: “Y-yea, it’s from a mixture of things really. You see, some plants, to protect their seeds, have c-c-certain kinds of oils in them that become thick when there’s a long dry spell. Th-th-th-th-those oils mix with a type of bacteria called actinomycetes w-which create that smell when it rains. Oh — hey! Look. It’s stopped.”
I’ve always imagined that these two do a lot of mundane things together like walking, bike riding, watching crappy movies, those kinds of things. They talk heavily about so many topics however that the activities many people may consider boring isn’t so to them.
Jerry likes asking RJ questions about things around him because, unlike Rick or Beth, RJ’s not a condescending dick due to Jerry’s ignorance and Jerry doesn’t feel like he has to put up a wall to mask it like he does with them.