His eyes.
It's the light in his eyes I blame.
Those gorgeous crystal clear blue eyes. Innocent and wise all at the same time. Those eyes that have seen so, so much. The rise and fall of civilizations. The destruction of planets and stars. The birth of new life.
They twinkle like the stars, like the constellations from whence he came.
Hopeful and wondering after all these years, he still has the curious eyes of a child.
When he looks you in the eyes, he sees your soul.
And I can't help but fall into them, time and time again.