Unlike the New Moon (which is about starting something new) the Full Moon is about reflecting on what was planted six months ago and how it is developing & manifesting.
When the Moon is full in far-seeing Sagittarius, the Sun is in near-sighted Gemini. Both these signs pertain to ideas and information. We must learn to balance the here and now with our future goals and plans.
Think back to the New Moon in Sagittarius in the beginning of December, what seeds did you plant then? What can you do now to nurture and grow them?
Now is the time to focus your attention on fostering your long term goals and higher principles.