Words are conceptual tools, so when a kid who is learning to talk first learns the magical power or this or that tool, they'll use it to death.
They're practicing with it to find its limitations and uses.
The first truly magical conceptual word most kids learn is "NO!"
It gives them the enormous conceptual power of the idea of the negative.
"MINE!" is their first conceptual understanding of the concept of the possessive.
You know how it is with kids, when they first discover the power of say, for example, a hammer, everything in their universe looks like nail.
Well, you kid apparently just learned the magic power of the concept of private property.
.