There are those who believe that the mandala carries messages from your inner most self. The idea is that drawing mandalas is a way to get in touch with your intuition, a path to self discovery.
Carl Jung believed that a mandala is "the the psychological expression of the totality of the self". For a period, he himself drew a daily mandala investigating it as a tool for self discovery. The artwork he created in this process has since been published as The Red Book. There is also a 'reader's edition', which is considerably less expensive but does not contain all the original artwork.
I find that I usually just draw without thinking too much about it. Sometimes the finished result is just an image to me, sometimes it seems to have more meaning. This one, mandala no 7 is an example of that. When I had finished the mandala it seemed to make a lot of sense. It says to me that we construct a few external layers to present to the outside world. Those layers have dark and light, ups and downs. This exterior might be patchy and uneven but it forms a cohesive, recognisable and whole shape nonetheless. Inside, however... well, that's more complicated. Colourful, but complicated.