And I think, ideally, most people follow this pattern. Problem is, my 4-month old daughter (and, I suspect, many, many other 4-month old daughters) haven't heard of this.
Might be relevant to you and parent: There was something on NPR this morning, about some mom adopting French parenting ideas - and one of the things the French are supposedly good at is getting their kids to sleep through the night at 4 months or so. Might be worth looking at :)