Where do ideas come from?

Where do ideas come from?  Isaac Asimov on creativity, from 1959.  Several things from the essay resonate with me, but most especially the notion that solitude is a requirement.  The innovations that I have come up with have always occurred to me while working alone.  The most recent example I can think of is the approach I came up with for making Java's numeric formatting and parsing run more efficiently: it came to me after thoroughly understanding what Java does now, what other approaches people have made, and thinking hard about the problem while alone in my office over the course of several days.  That pattern seems entirely typical.  Asimov's references to the need for an informal, intimate atmosphere amongst a team also resonates.

It's interesting to note that the guy who wrote this essay is best known for his science fiction works, then for his non-fiction books about science, and then for his remarkable productivity (he still holds the record for the number of published books written by a single author)...