You are quite right. All of the information is in the manual, and if only everyone would spend their time reading the manual there wouldn't be so many questions

You are quite right. All of the information is in the manual, and if only everyone would spend their time reading the manual there wouldn't be so many questions on SO. However, the volume of information in most manuals is also the problem. If everyone read the whole manual, a lot of time would be collectively wasted because most of the information is not useful or relevant to what each individual developer is trying to do. In my opinion manuals should be written in several tiers of detail. Admittedly, a lot of software developers already publish documentation this way and these basic questions still get submitted to SO.