Good ideas are always crazy until they are not – Elon Musk – Larry Page
I am not sure who said this quote, the internet of full of references to Elon musk, with few to Larry Page. I personally think it was said by Larry Page the cofounder of Google.
At first glance the average Joe might think it must be Elon Musk, as Elon is known for his crazy ideas like reusable rockets or self driving cars. But keep in mind that Google also have a whole department of crazy ideas (used to be called project X).
Good ideas are always crazy until they are not
Concerning the big ideas, like the ones brought to fruition by Google, SpaceX, or other big tech companies, i have nothing more to add.
As for the good ideas that every good entrepreneur have from time to time, they would sound crazy because others have not done them yet, and might sound absurd even. Once executed, you realize that not only they are possible but also they make sense.