The more doodles I add to a mind map, the more useful it is in helping me understand how concepts fit together. Because mind maps explicitly focus on how ideas are connected to one another, they help me visually identify the gaps in my knowledge, making it easy to identify what I'm missing. As mind maps take shape, my mind can't help but find ways to fill in the open spaces, which oftens leads to valuable "Aha!" moments when learning something new, or brainstorming ideas. So, if you're feeling stuck, get some paper and start drawing. You won't be disappointed.
As a bonus, by picturing where I drew something on the page, or where I drew it in relation to a particular color or shape, I remember more details about the subject of my mind map than I would otherwise.