I get this too! I don't judge them, I listen because they've probably been wanting to do that for a long time. Another thing that happens with me is that "tough" types will approach me and start acting really friendly with me, whereas with other people they're always angry and intimidating. I think there's something about me that's really disarming but like you, I have no idea what it is!
I have no idea why but this happens with most people in my family and we can even trace it back to my great grandma.
I think it does come down to listening actively, but also by sharing a sense of openness and vulnerability. When you're honest about yourself with others, they're more likely to be honest with you.
Autism is genetic, and many undiagnosed autistic children will become much harder to diagnose as adults because they will over adjust from their social awkwardness and become incredibly active listeners.
They'll often be told they're "easy to talk/open up to" because they maintain great eye contact, nod along and give little responses throughout a story.
I'm not saying you're autistic necessarily, but the experience you're explaining is one that I've had and many people I've known have had