The ancient Greeks believed that there was a special class of deity — the Muses — who collectively provided the inspiration that begat human invention and achievement in the arts and sciences. The reality may be even more interesting than this.
I have noticed that random meetings with individual people at some opportune moment can often inspire me to work on something new. Perhaps I’ll be thinking about some idea, somewhere in the back of my mind, but then I will have a great conversation with someone who shares that interest or particular set of obsessions. Suddenly my brain shifts from dreaming mode to problem-solving mode. The very fact that somebody else is interested in the same thing creates a feeling of reality around the goal, and my mind instinctively starts to move toward that reality.
At any moment, you might run into somebody — a colleague or just a friend of a friend — who has been thinking about some of the same things that you have been thinking about. Perhaps our brains are wired for such meetings. They invoke a feeling of community which elevates and focuses those thoughts in our minds, and we immediately become more inspired and creative.
In a sense, we are all the Muses for each other.