Nobody in a shared kitchen ever eats the last piece of cake. They cut it in half, take one half, and leave the other, because then they haven’t taken the last piece. The next person does the same. By four o’clock there is a sliver on the plate thin enough to read through, and it is still not the last piece, because nobody has eaten it. Zeno said you could never reach the end of anything by halves. He was wrong about arrows and right about cake.