It’s a long talk, but the most important piece to pull away is that “Great companies” can lose money, and be valued accurately and well, and that there are two valuation methods: numbers and stories, and both of those valuation methods are based on societies perception of them at the current moment.
There was a scientist in the 1900s - Francis Galton - who believed that the “herd” mentality of people, although can be associated with extremely irrational behavior and panic hysteria, can also provide a lot of value, so he bought an Ox, and had a crowd of people guess its weight (for a prize). The average guess of the crowd ended up being within 1 pound of the real weight of the Ox.
I think valuations live somewhere between humanity’s irrational brain and the wisdom of the crowds.