Evolution
The focus and organization of your maps starts to shift. You come up with a new way to organize things. You don’t go and change all the old mind maps but gradually start to do things in a new way. It doesn’t have to be a result of any especially intelligent design, some of the changes just happen, some even by chance. You hit a wrong keyboard shortcut and accidentally discover a quick way to represent the stage of your project tasks by using colors. After a year you look back at your old maps and you notice that a big change has taken place.