Attention wanders easily. Lack of color and other visual qualities handicap memory. Traditional notes aid forgetting not memory. Memory is naturally associative, not linear. Any idea probably has thousands of links in your mind.
Mind maps allow associations and links to be recorded and reinforced.
Mind maps use just key words and key images, allowing a lot more information to be put on a page. Because mind maps are more visual and depict associations between key words, they are much easier to recall than linear notes. Starting from the center of the page rather than top-left corner allows you to work out in all directions. The organization of a mind map reflects the way your own brain organizes ideas. Mind maps are easy to review.