Believe me, the sight of all those books going up in flames hurt me too…but then I started to think about it a little more. Yeah, it’s the Grimms’ history…but a lot of it is a history of remorseless, unforgiving brutality and ruthless murder.

The Grimms are not a long line of people like Nick, remember. They weren’t feared because they were reasonable and compassionate. Even Nick has been shown at times to be horrified and disgusted by his ancestors’ actions.

So…on the one hand yes, Juliette burned down his trailer full of vital information but on the other, she didn’t by any means burn his family history. Nick’s family history is his memories of his aunt and his father and mother, most of which actually had nothing to do with the Wesen world and the Grimm legacy. 

There’s actually no reason whatsoever to think Nick had nothing of his family other than what was in that trailer. The “normal” things, like photo albums, cherished memories of the childhood he had with Marie? I doubt they were there. Why would they be? And why on earth would he value his family’s long history of blood and brutality over that?