There were five principal reasons why my relationship with Rosie encountered difficulties after our relocation to New York: 1. For non USA natives there is frequent opportunity for confusion. 2. Residing in an apartment used by a rock star to refrigerate his beer. 3. The presence of my best friend Gene. 4. Convincing the social worker that I was suitable for continued residence in the US. 5. Rosie's hormonally-induced behaviour, and my meltdown due to unplanned pregnancy. As Don prepares for fatherhood, he discovers he has to take into account a new force in his life—The Rosie Effect.