+1 on the frustration with cups of ingredients and sticks of butter. The idea of measuring ingredients by volume rather than weight is so frustrating when cooking. For many ingredients it's an illustration of the amounts not being that critical, but it just makes recipes difficult to reproduce, oh and the whole Fahrenheit thing is hard to understand too. However, I do have to recognise that I still think in miles for distance and speed, but that is in part due to that being the unit used on road signs and car speed, but I'd also be perfectly comfortable switching to km. To return to
@moto748 's point about gallons - it is difficult when the same name is being used for a different unit and really if that's the only unit given then you're in the experimental zone when it comes to reproducing a recipe!