I can see that maybe I was violently agreeing with the second part as I can't know why the parent comment was saying realizing the invention is hard. But I thin

I can see that maybe I was violently agreeing with the second part as I can't know why the parent comment was saying realizing the invention is hard. But I think my quibble with the first part stands. I'm not convinced that this idea was extremely common in 1919, it seems quite visionary to me to have this idea at that time. EDIT: I also think that the premise of ideas are easy and realization is hard implies that it would be contemporaries having the ideas and doing the realization. Otherwise all we're really saying is that ideas precede realization.