Social interaction and imitation are key to understanding daily behavior. Neuroscience has focused new attention on these phenomena, and a newly discovered class of cells, mirror neurons, has provided evidence that action understanding is influenced by visually triggered imitation. These findings suggest that people can understand the actions of other individuals because they resonate in the same sensory motor circuits that would be involved if they performed the same actions themselves. Hypotheses have been posed regarding whether the same neural mechanisms underlie not only the understanding of behavior but also its imitation. This essay discusses three aspects of these echoes: suggestive evidence from the behavior, electroencephalogram- and magnetoencephalogram-rerecorded readiness potentials and motor commands through a brain-computer interface suggesting that the understanding of seen actions is often accompanied by covert mimicry; a hypothesis of why the rapidly fading echo vanished from scientific discourse for about a century; and a proposal on how action understanding is influenced by time-locked imitative fMRI. It is well established that the observation, reading, or imagination of actions produces brain activations that overlap or border with, but are distinct from, those seen during action execution. These activations are increasingly recognized as playing an important role in mediating our capacity to understand the actions of others. Observed daily manual behavior is spontaneously coded in an observer’s motor system “mirroring” the grasping act with a modulation of discharge of mirror neurons encoding an object’s size. This study demonstrates the latter: a specular, online motor compliance request delivered via a miniature robotic arm triggered mirror neuron activity as the observer anticipated the human enlarging the bowl. However, when the human is covertly prompted by an experimenter to grasp the large bowl while pretending to reach for the small one, discharge encoding size decreases back to the level observed with the veridical grasp.