Aquarius's are usually non-conformists or daydreamers, choosing to express themselves by speaking, acting, or dressing differently than their peers. You may find that you blend in while wearing your uniform and may try to do things to stand out from the crowd and it's possible you could go to the extent of getting yourself into trouble, maybe without meaning to.
You have ideas and are a bit of a visionary, often able to think far ahead into the future. While in the military you may find your creativity is stunted due the repetitive nature of drills and military lifestyle. You can be erratic and emotional at times, and being a wild card may work against you in an institution where they want everyone to be the same.
But it's possible your indecisive daydreamer side may enjoy the structure of the military. Having so many decisions made for you will clear up your brain to think about other stuff. Being unconventional may help you think of new ways to solve problems during training or times of war ect. You are able to think of of many possible outcomes to a scenario and will almost always choose the option that helps the needs of the many instead of the needs of the few.
Aquariuses are generally humanitarians and enjoy helping others. You may find that you enjoy being a role model to others and will like the idea of serving your country, helping to sandbag, rebuild or protect communities.
Depending on how "true" of an Aquarius you are will depend on how successful you are in the army.