When I started studying philosophy, I used to dislike any historical approach. Investigating into, e.g., the history of the antecedents of Cusanus or Hegel seemed to me at least a boring distraction from their powerful theories or even a nuisance to their understanding —since through history they became less "out of the blue" and hence ended up looking less powerful. I liked even less historiographical accounts about the history of philosophy (e.g., how was Berkeley interpreted in the late XVIII c. Germany), which seemed to me an end in itself I did not want to have nothing to do with.
Now I know that what I ignore will influence me without me being aware of it, hence in a subtle and dangerous way. Therefore, I started studying philosophy as the history of its development. More recently, I am also becoming aware of the importance of the study of historiography. If one is not aware of historiographical trends and fashions, e.g., one might tend to think that one reads are historical (or textual or archaeological…) data, whereas the author of the study might have played a significant role in collecting them and sorting them out.
I have been led to think a lot about this topic since the last Coffee Break Conference, where Giovanni Ciotti dealt with it as for linguistics (explaining, e.g., how the history of linguistics may influence our understanding of what a "root" is, although this should be a "scientific" term) and Mark Schneider dedicated an enlightening round-table to Historiography.
More recently (for me), Srilata Raman, in the book I frequently referred to in the last week, is well aware of the risk of taking historiographical models as if they were harmless description of reality as it is. She points out, for instance, that the monkey/kitten simile is very recent (XIX c.) and that Tamil historiography on Srivaisnavism used history "as a vehicle for locating groups and people [in this case the Tamils] and giving them a past taht suits their present or encourages their sense of the future" (Michael Bentley, quoted in Raman 2007: 15).
Have you ever come across similar instances, where being or not being aware of some historiographical background has saved you from a major misinterpretation?
On the importance of studying history, see here.