you just talk to people and convince them lol its not that hard. i didn't know i was good at sales turns out i just have to be me and people like what i gotta say
It's possible that you have natural charisma or talent. But I'd say the people on HN probably lean towards more introverted so sales is probably quite hard for them
Creating a good product requires lots of interaction with your target customers. You can call the "sales" in the beginning, but it's really understanding how to tweak your product from an idea to solve a problem into something that fits into the customer's workflows and solves their problems. The only way to really validate the product is to see who pays money for it.