mapping and associativity in brain

Have you ever tried to thought how thoughts or more precisely how data is evolved in human mind. It has been more than few years when I was trying to think hard on some topic, I was not getting anything in my mind related to that topic. But, when I remembered something then very soon I was also able to remember other details also about the same topic.
How do we put data in our mind, sequentially. One thing is to sure that to think you need something, some data to work upon. When one starts thinking about any topic then first something comes in your mind and then slowly other things also keep coming. From this new data, some is the resultant of the processing of previous data and some matching data is already found in your mind, in your memory.
Whenever someone tries to remember any past data, it seems to be stored as images, all connected and linked to each other. You remember a particular one and you find a full chain of related data. For example, if some word like, country comes to your mind then depending upon the state of your mind you start thinking in a particular direction about that country. You may start thinking about the population of that country, if so, then you may start thinking about the division of population geographically. This may trigger a thought about the terrains or mountains or rivers in that country. As thoughts are based on data so, one can go to any direction depending on the availability and associativity of data.