Even when we have documentation of the past, it can still be hard to figure out what actually happened. In this article from the BBC, the author discusses the particular issues that surround attempts to understand how European Medieval and Renaissance knights fought. In this case, there is a lot of documentation–more than 80 surviving “fight books”–and even illustrations. The issue is that, without contextual things that those past knights may have taken for granted, modern scholars and fencers often lack a solid starting point. Another issue is that the perspective of the illustrations in these books is sometimes difficult to figure out. This is a great example of the fact that it is sometimes better to pass knowledge on personally instead of just trying to learn things from a book.
link to The Lost Medieval Sword Fighting Techiniques No One Can Decode