Having a "monkey mind" is a Buddhist term to describe a mind that is constantly darting from one thing to another; where there is a persistent churn of thoughts in the undisciplined mind. In other words as opposed to one's attention being focused and calm, it is unsettled, restless and even indecisive, thus often leading to confusion. Within the spiritual (and/or magical) scene, it can be rather easy to develop "monkey mind" as there is "so much to learn".
One of the greatest misconceptions people tend to make is to attempt it all. Instead of focusing on one aspect, they flit from subject, technique or even spiritual path in an attempt to "learn more", to "gain greater knowledge" etc. While, in some instances, this objective may be achieved, when it is, however, it is usually at a shallower level (or lesser degree) than if the person slowed down, and took the time to properly submerse themselves into the said subject, technique or path. How can we gain a true understanding or appreciation for something if we merely skim the surface?
Most spiritual traditions tend to require the dedicant or initiate to spend time studying the texts or sacred writings and/or philosophies, that is except within Paganism as we are "anti-dogma" and "not a book" spiritual path. (If these points are indeed accurate, why are there so many Pagan "101" books available? Clearly, people do require at least some form of "structure" whereby the governing "principles" tend to have moved from an organisation to an individual, ie author). Even within my own tradition, despite the misconception that "everything is published", a great deal of self work in required in order to fully understand and appreciate the underlying philosophies contained within pieces of liturgy (a term itself that is not often used within Pagan traditions - yet pieces such as "The Charge of the Goddess" actually do fall into this category). Yet, instead of taking time to study and fully embrace (or at least understand) the underlying philosophies of even a modern spiritual path, the temptation to develop a "monkey mind" is more appealing - after all, if we do not attend every lecture, group activity, camp etc we might actually miss out of something.
What is overlooked, especially from a more traditional point of view, is that all these "somethings" or snippets of "somethings" that we gather as we flit about, can actually be detrimental in our deeper understanding of the path that we are dedicated to or initiated into. And I should point out that there is a huge difference between "gathering knowledge" if you are a solitary practitioner walking your own path compared to a dedicate/initiate of a path - naturally, as an initiate and teacher of a set tradition, I am talking about the latter.)
As a teacher, I do not like to "withhold" or "prevent" students from gaining knowledge or increasing their experiences. What does concern me is when their quest actually encourages the develop of "monkey mind" for this can have a number of side effects. Some of these include the additional stress and anxiety due to the "fear" that they may "miss" out on something. Another side effect can be "confusion" when the new knowledge gained (albeit somewhat superficial) actually contradicts what has been taught within the tradition. Neither anxiety or additional confusion is truly beneficial to your Self as a whole.
At the end of the day, we each have the free will to walk the spiritual path that aligns best with our inner calling. The only way we are going to truly understand which path this indeed is for us, is when we learn to control our "monkey mind", our design to become an instant spiritual jack-of-all-trades and focus on one thing at a time. And if you are unable to do just this, maybe you should spend sometime contemplating whether following a traditionally set path is actually for you.