Every Assumption and Letterwriter Bias

This has been a tip before...but since I just had to be painfully reminded of this myself: think about every assumption you've made. What would happen if you dropped one?

I was looking for a man written about in an 1887 letter--with an apparent German name. The letter writer was actually writing about a man with a very English name. She just "translated" his name into German. When I quit looking for a "German," I found him.