One of the many quotes by Homer Simpson is, "We haven't tried anything and we're all out of ideas!"

We shoot down our ideas all the time. We do it even before we consider it as a possibility. 

This is a good evolutionary trait to conserve our resources and effort in order to spend them on the ideas that are most likely to have a return on the investment we make. 

This helped us out when the resources we had and the safety with which we could explore new ideas was very low. 

There was no appetite for taking on moonshots.

But, fast forward to today, and a lot of the scarcity and fears we face are the ones that we can dismiss instead of the ideas that they are preventing us from pursuing. 

Today, very often, the safe thing to do is to take the moonshot.