The law of supply and demand assumes purely rational actors in every situation, it also assumes commodities are comparable/identical and are largely mobile and

The law of supply and demand assumes purely rational actors in every situation, it also assumes commodities are comparable/identical and are largely mobile and transferable. This doesn't apply to things like healthcare as others have mentioned, but also education (people are told their whole lives that they need to go to a good college, so people often make the poor financial choice to attend the better school), and in many cases housing (not wanting or able to leave the community they have only known, so they are willing to rent burden themselves in order to live somewhere). Add on the fact that many of these things aren't as standard and transferable and you notice why these are the major markets that experience serious distortions in both a free market and a highly regulated one.