Neptune is the second of the generational planets, spending fourteen years in each sign. Everyone born within that period will have Neptune in the same sign. By itself, this placement is not the most important factor in your chart.
However, it symbolizes what was going on in the world at the time you were born, and this has left an imprint on you. You and members of your generation are each imbued with this particular energy, and in some ways it characterizes everyone born during this time. Each individual will express it in their own way, some more strongly than others. The Neptune-in-Aquarius generation (born between 1998 and 2012) will refine the areas of science and technology, and will bring a new sensibility to their uses. You and your generation will be at the forefront of using science and technology for nonacademic reasons, and perhaps in pursuit of spiritual goals. Sounds ironic, but that is the gift of the Neptune in Aquarius generation: transcending the technical to the spiritual.