Every Human Brain is like this.... It is divided in to many Sectors. It has too many data's to access but the problem is that, it can be operated only by the Owner. Each and every situation's are saved separately. If any one want to access others information, the best means of communication is either by swimming/ walking/ flying/ hanging around in their memory, Only if you know to tackle that person's mind. Else, due to the over knowledge of that person, you may tend to drown yourself with in them...
So before reading others mind, first read them well and then read their behaviour and act accordingly(Wisely)!