A rainbow is a full circle of light centered around the point opposite the sun, but grounded we can only see the arc above the horizon. You can only see a rainbow with your back to the sun.

Just take a garden hose with your back to the sun and spray. You'll make a rainbow.

This was going full circle for him.

It's now come full circle.

When I set a glass prism on a windowsill and allow the sun to flood through it, a spectrum of colors dances on the floor. What we call "white" is a rainbow of colored rays packed into a small space. The prism sets them free. Love is the white light of emotion.

The light wave is then reflected off the back of the raindrop's surface and bends as it goes outward at different angles.