There is difficulty in thinking of an idea even when all the facts are on the table

From How Do People Get New Ideas? by Isaac Asimov.

The history of human thought would make it seem that there is difficulty in thinking of an idea even when all the facts are on the table. Making the cross-connection requires a certain daring. It must, for any cross-connection that does not require daring is performed at once by many and develops not as a “new idea,” but as a mere “corollary of an old idea.