Children, just like adults, pay attention to differences in the first place. These observations are well documented by neurologists and psychologists.
One notices movement, or a boundary between light and dark. One reacts to bodies of temperature different from ambient temperature, i.e. warm or cold. On the other hand, things and phenomena lacking special features, i.e. similar to the surroundings, escape our attention.
A child watching his buddy on a swing notices mainly the changes: the beginning of swinging, the acceleration of the swing, slowing down, halting (friction). Classical mechanics taught at school offers description of phenomena invariant under time reflection, e.g. harmonic motion with mechanical energy conservation. Such phenomena go unnoticed by a child since they do not occur in everyday life. In model situations presented at school, child's attention also concentrates on changes in motion, not on its regularities. Uniform motion is uninteresting while the question AS TO ITS ORIGIN is intriguing and important. And it is this very question that is usually neglected!
There are approaches to mechanics and thermodynamics teaching that build on this feature of the mind. For example the proposal by Jon Ogborn [9] starts the study of heat from non-equilibrium thermodynamics. Beginning electricity teaching with discussing currents, and not with electrostatics, as was done by Piekara long ago, has been advocated in the US by Melvin Steinberg. This remains in agreement with the nature of child's perceptiveness and her interests. It is fairly closely followed by the Karlsruhe school (Falk and Hermann) [10].