The Moon is a slut.

What is gravity?

From Wikipedia online:
"While a great deal is now known about the properties of gravity, the ultimate cause of the gravitational force remains an open question and gravity remains an important topic of scientific research."

I'm sitting in my apartment, and for some reason all my stuff is stuck to the floor. My keyboard is lying on my lap, and my hair is not all waving around recklessly.
These are all consequences of gravity, just like the fact that all of the liquid water is lying in rivers and oceans rather than flying around in the air.
But the moon is not stuck to the Earth, it's far away, still it seems to want to stay near. Like children who have grown yet still wish to remain close to their parents and siblings, it's a force that is completely unexplainable to those who do not experience the particular pull that causes the attraction.
Robots for instance. Robots will never understand love. A robot will never feel any affection for it's owner, and would be just as happy serving one owner for 50 years as the next.

If a Robot, a Man, and the Moon all set off together on an interstellar voyage, the moon wouldn't get far before it was captured by the gravitational field of the first planet or star that it came across. The moon is a slut.
The human would continue to travel with the Robot, but would eventually get lonely and seek out sentient life forms. Whether she was green, had antennae, or whatever, the Man's need for female sentient companionship would increase until he got so lonely that he was willing to accept the tentacle blob from Planet Zargon as a mate. Then he would make a home with her and his journey would be over. Men need Women

The Robot-well does anybody really care what happens to the Robot?