do we 'own' ideas?

Before I started a company, I probably would have said yes. After a few years in the startup world, I'm not so sure anymore.

There is, after all, a reason why inventions are patentable and ideas aren't.

Execution is king.

I mean, even if you don't did a startup, you will notice that you have ideas you told nobody and they get still executed by someone.

In a way we do. Investors are pushing story that ideas are not worth anything. Of course they are, otherwise those studios they set-up would just crank out hit after hit, because they can design that business perfectly.