30 minutes with a stranger

You need structure for this to be amazing. Talking to a random person at a train station and asking for their destination isn't a meaningful conversation, even if they divulge a bit more about their travel plans.

Instead, I've personally really enjoyed talking to strangers while having a meal in the dining car of Amtrak trains, where they will force you to sit with three other people. This gives you more time together and more structure. I've talked to a retired real estate agent who told me stories about the houses his clients bought; I've talked to an old lady who told me first hand stories of the AIDS pandemic in the 1980s.