Where Do Shared Ideas Exist?

If I have an idea, you can argue that it exists in the biochemical stew that is my brain. If I share that idea, whether it be through speech, through writing, or through smoke signals, it now has an existence that is outside a person or persons.

Where? Where do shared ideas exist?

Related questions: Where do ideas come from? What is an idea? What does it mean to share something?

How Can We Turn Ideas Into Actions?

I have plenty of ideas. In fact, I have so many ideas that it is often difficult to focus on just one, and so I never take action. Or a plan seems so big that it can be overwhelming to try to accomplish. Or laziness gets the best of you and nothing ever happens.

There are many reasons why a plan might never come to fruition. But how can we avoid that fate and turn our thoughts into reality?

Related questions: Where do ideas come from? How can we be more productive?  How important is the repetition in our lives?