A jar full of rocks

After having some soup and oranges for supper last night, Bon asked me whether I had prepared any tea for her. Knowing that she had also had a pretty filling dinner, I turned to her in disbelief and asked, "are you serious?! You still have room for more?!?" This resulted in the following (rather baffling) conversation:

Bon: Well...say you had a jar and you filled it up with big rocks
Ky: Big rocks?
Bon: Yeh, like bricks.
Ky: You want me to fill a jar with bricks?
Bon: Ok so maybe they're just big sized rocks...anyway, the POINT is you fill the jar with big rocks.
Ky: Ok...**kinda lost already...**
Bon: So is the jar full?
Ky: Er...
Bon: Yes. Yes, the jar is full.
Ky: ...**not quite following**
Bon: Ok, then you fill the jar again with middle sized rocks, yeh?
Ky: Uh...right, middle sized rocks.
Bon: And is the jar full?
Ky: Uh...yes?
Bon: That's right, it's full! Ok, then finally you fill the jar with small rocks, like pebbles and sand.
Ky: **really really lost now** Umm....oooook......
Bon: And is it really full?
Ky: ....yes...?
Bon: Well....that jar's my stomach! The sand is like water, so there's always room for tea!
Ky: ?!?! Huh wha?!?!

Bon, you're such a creative individual. Only the truly talented would be able to come up with such a bizarre analogy for their stomachs.