[clemParis]

You can tidy your room and the mess (that they mistake for entropy) would be reduced. The 2nd law of thermodynamics states that in an isolated system the entropy is always increasing (or at best constant), so the room analogy does not work.

[testing312]

Tidying your room would be adding energy to the system, to make it tidy. This is still in line woth thermodynamics where adding energy can decrease entropy

[AtHeartEngineer]

You have to add energy to make it messy as well

[dasil003]

"Tidy" is a subjective quality, not an objective physical one. It does take mental energy to tidy a room, and without that effort it will tend to get messy through use. As long as you don't confuse mental energy for physical energy and tidiness for entropy in the literal sense, then the analogy works surprisingly well.

[amelius]

Tidying it requires external energy, which is what is happening (unless the person stays in the room in which case the mess will become even bigger).