That attitude has sunk many business ideas in recent years. Maybe it worked in times past — but then again, maybe it didn't. These days, a "mine" attitude will slow you down and keep you underground.
A collaborative spirit, sharing ideas and building on the collective smarts make us all better. One might say "iron sharpens iron" or "together we're smarter" – and every one can find profit in some way by doing so.
Look, once you put your ideas out there on a blog post or Twitter, it's time-stamped (yours). But it's also shared with a ton of folks who believe – live and work by – a Creative Commons mentality (ours). What would Michael Jordan have won if he didn't learn to share the ball?
I'm not suggesting you give away the farm, and all your recipe secrets, but you'll get more if you give more.
As we move forward, I sense a larger danger in a "mine" attitude – alienation. Rather than looking brilliant, you may come across as selfish.