In this talk, the speaker talked about the importance of having a thorough understanding of everything in the world, rather than holding one stereotype. When people have very narrow access to a thing for a long time, they tend to take it for granted that this is the whole perspective of the object.
This is related to my experience of creating a project. When I do the project, I always tend to see what the former people did in the similar project and always question myself about what is this project supposed to be like. If I found that there are limited styles of doing the project, then I will think that this is the right way and the only way to do it. This thought will largely decrease my creativity and it is also the reason that I always ask a lot of people for their opinions to see if there are any other potentials.
In my opinion, the reason that people, like the speaker, advocate for getting a thorough understanding of everything is that this phenomenon threatened the later generations creation and development of knowledge. If people have the same narrow perspective for a really long time, it is really hard to change their mind, since people will stick to the initial impression. So, when later generations refer to their work, they will build everything on the wrong basis. In the end, those faults will accumulate and create a disaster of the world.