I know what you mean about not thinking you would nurse a toddler. Neither did I, but I'm so grateful for this experience. Ds (20 mo.) occasionally says, "Mmmmm, boobies." And every time he's finished nursing he waves at my chest and says, "Bye bye, boobies."
A couple of months ago, I showed him how I can manually express milk. Of course, it squirted him in the face and he thought it was hilarious. Now he'll frequently grab my boob and squeeze as hard as he can, trying to get milk to come out. He says, "Milk, milk," and wants me to do it. This is the only time he calls it "milk;" the rest of the time it's "boobie juice." So cute.