Every genealogist knows (I hope!) that assumptions are a bad thing. They make us blind to other possibilities, and they are often wrong. I always thought I was careful in not making any, but recently I caught an assumption I made years ago and never bothered to verify!
I've always know that the rather large van Aken family that's living in my village is related to us through my mother's side of the family. I always assumed (yes, there is that dreaded word!) that this relation was through my maternal grandmother, Henriette Geertruida Lamboo, since the Lamboo family, just like the van Aken family, is from these parts even way, way back. In a recent conversation with my mother, however, I discovered differently! All because I asked the simple question of where exactly the relation was made. My mother told me that her paternal aunt, Anna Knura, married a van Aken!
Now why did I make this assumption? I made it because my grandfather's family came from Germany, and I never expected anybody else here except my grandfather. What a big mistake that turned out to be! My great-aunt Anna was here before my grandfather, in fact, my grandfather moved in with her when he just arrived in the Netherlands. From newspaper records that record the comings and goings of the population, I have found that numerous Knura's (all brothers and sisters of my grandfather) have come and gone in this area. They arrived, worked and/or stayed a few years, then moved back to Germany. Some even repeated this proces. How much information I would've overlooked if I hadn't known that the connection to the van Aken's was through the Knura branch!
The lesson here? Always, always verify your information, no matter how 'obvious' it appears!