Consider a spherical, sealed glass container of gas. Further suppose that the gas inside is all the same -like helium in a balloon. Room temperature and stable. Everything equal inside...but it's not. The individual gas atoms in the container have unequal energies because there's a range--a statistical distribution--of energies present: Some atoms move more slowly than others, some more quickly, some much more quickly.
How can we make things fair? How can we make it such that each individual (atom) has the same energy as its next nearest neighbor? We cannot. The only way to approach that state is to remove energy from the entire system. Cool the economy. Everything slows. Eventually, approaching zero Kelvin, all motion stops. Of course catastrophic things like condensation (downsizing from gas to liquid) and solidification (loss of liquidity) occur along the way. But the goal is achieved: every atom is finally the same (or nearly the same) energywise.
[added: an explanation here: link]