It's really easy to dismiss and poke holes in peoples' ideas. The funny thing is that you usually walk away from that feeling pretty smart and full of yourself because you're mostly right.
Then you find out that you called it all wrong. And if you're introspective, you'll realize that you weren't just wrong in your thinking in the moment, you'll remember that you are actually a flawed, small person who knows very very little.
Early on, when I knew even less than I know now, I had a conversation with a guy named Gary Chou who then worked at USV. He's a model for me on how to treat a green person starting out. He didn't seem to be trying to answer the question, "does this suck?" or "can this be a $100M ARR business?" When we talked about what I was working on, he really sought to find out what was interesting about it, how people were using it, and what it could mean and become.