How reliable is instinct in gauging whether or not a person is interested in you?

I’m sure we’ve all been in the situation before. You just sense that the other person is interested in you.
I’m sure there are plenty of body language cues or physical reactions that supposedly give us a heads up when someone is attracted to us. But what about instinct? Is it reliable?
How often do you trust your gut when you get a feeling that someone is interested in you romantically?
Do you believe that it is accurate in most cases, but perhaps certain circumstances might cause the other person to deny their attraction?

Just for the record, I am married.. so this is just a question I ask out of curiosity. I always try to trust my gut, but I notice that many people hesitate to trust their instinct when dating. I wonder what other jellies think about what role instinct plays in the dating world. So “just ask them” isn’t really the answer I’m looking for.