The person will delve deeper into the subject giving you more information to work with and more paths for you choose from.
If they say something like: “Oh, I don’t know” at first, don’t give up. Prod a little further. Ask again. They do know, they just have to think about a bit more. And as they start to open up the conversation becomes more interesting because it’s not on auto-pilot anymore.
Tightening up
When in conversation with someone you just meet or when the usual few topics are exhausted an awkward silence or mood might appear. Or you might just become nervous not knowing exactly why.