Does a pillow know it's a pillow?

Probably not.

But a pillow is stuffed with a very large number of atoms. And atoms that are closely associated are said to be entangled.

Now, entanglement is an idea borrowed from quantum physics. Its definition is normally limited to what can happen when subatomic particles interact. Quantum physicists have mathematics they can use to predict the results of those interactions. But the math gets very complicated when there are more than a few particles interacting, so it's not like they can use it to predict what will happen to the atoms in a pillow.

All this entanglement idea really tells us is that if the atoms in a pillow interact, it can affect what happens to them later. In other words, it tells us that atoms have memories. Because that's what memories are, connections to the past that can affect what happens later.

Anyway, a pillow doesn't have to know it's a pillow in order to act like a pillow. It's pillowness is built in. So how does a pillow know how to act? That depends on its parts. If it's stuffed with fluffy feathers, or foamy rubber, then it's really the feathers or the rubber that have to know how to act. Featheryness or rubberyness seem to be built in too.

Just like atoms, feathers and rubber have memories. Complicated entanglements that constrain their behaviors to predictable patterns.

We tend to associate memories with our minds. Without memories our minds would have nothing to do. Feathers and rubber have to remember how to be feathery or rubbery in case they are called upon to be fluffy or foamy again. Our minds serve many similar functions.

An important function of our minds is to tell our bodies what we want them to do. Luckily, there are many things our bodies know how to do without having to be told.

The body is a collection of organs, all of which must have minds of their own. We hear of muscle memory, but that just scratches the surface. Actions like walking, standing still, driving a car, are at least semi-automatic. The stomach reminds us when it's hungry, the heart and lungs don't need our attention to function. Other organs also function on their own. Active body parts have minds which enable them to perform the actions they need to do. And they all talk to us, if we listen.

Like pillows, things that are not clearly active, even rocks and such, must also have memory minds, if only to hold their forms. Simply holding a form is also a way of talking.

As Milton said, they also serve who only stand and wait.