I agree that babies act differently from the start. It is also true that a very small number of babies are truly inconsolable, and most babies go through periods of being extremely hard to console. Often with good reason. For instance both of mine developed a painful problem with gas at about 2 months of age.

That said, the combination of strategies that I described works amazingly well. The fact that they won't _always_ work doesn't diminish how much they help.