Regarding the second law of thermodynamics

I will try to explain as clearly as I can. First of all, it's not like what you put in a box will take any shape. It can take many shapes. To answer your question, consider a closed box with gas inside. If initially the gas is all concentrated in a bag in one corner, and now the bag is torn open. The gas will begin to disperse in the box. What does it mean to disperse? To move between all possible states (each particle can be anywhere and at any speed). When you look at such a situation over time, you will see a uniformly distributed gas throughout the entire box all the time. Therefore, there is a direction to the process: from a concentrated gas to a gas dispersed in the box. The reverse process will not happen. What does it mean not to happen? Think about a situation where you start with a gas that is dispersed throughout the entire box and follow it. There may be one moment when it is all concentrated in one corner (as with the bag). But it will be for one moment and this special state will disappear immediately. Thermodynamics deals with constant states (what is called equilibrium). Such a state has a direction: from the concentrated state to the dispersed state and not vice versa. This is even though each microscopic state has similar weight and you can reach from any state to any other state symmetrically. To understand how this happens, entropy calculations must be done, but intuitively it is completely clear.