@davidpgil well two different features your describing. One is its size, mass and gravitational attraction. Thats one thing to discuss, the other is the fact that it has the same side facing us...

the first part we can easily show with numbers that the moon is orbiting us exactly as we might expect. Its size, mass and distance are all the same as any other moon or planet and the math works out just fine.

The fact that one side always faces us may seem weird but it is easily explained. this is true for most moons in the universe in fact and is the norm. When the moon was first captured by earth it was almost certainly rotating. However there is an effect called tidal-locking that causes a smaller object like a moon rotating around a planet in close proximatiy over a period of time to stop rotating such that one face will always face the planet. Its not coincidence.

the reason tidal-locking happens is, as the name suggests, due to deformations similar to the tides. The tides on earth cause water to bulge on the side the moon is on (And the opposite). As the moon moves this bulge moves to follow it. This doesn't just effect the water though but even the rock itself. The moon and the earth are physically distorted in shape as they orbit each other ever so slightly. If the moon were rotating it would constantly be deformed as it turns. This deformation would result in the rotational energy being lost as internal heat. Eventually the rotation stop when its energy is lost as heat, causing the tidal lock and the single face of the moon.