If I end up talking to a strange and a subject of common interest and/or expertise has been found, I have no problem maintaining a conversation with them, leadi

If I end up talking to a strange and a subject of common interest and/or expertise has been found, I have no problem maintaining a conversation with them, leading up to even exchanging contact information so that we could catch up again later. But if no such common subject of interest can be established, then that often leads to awkward moments and conversations cut short. I think the people that are good at this can sustain conversations and interest even in that second situation. Maybe it's like you say - asking insightful questions about a topic they might be knowledgeable about but you're not. I can understand the concept, but I always feel very awkward, probing, and intrusive doing it unless they start passionately spilling the beans immediately. I would say almost every friend I made beyond high school was because we had some kind of common interest or passion.