The Sun / Moon Opposition indicates that you were born at or near the Full Moon. The modern psychological approach would seen this as a conflict between your creative will - your conscious and your emotions, feelings and need to nurture or be nurtured. The Sun is outgoing and active, the Moon passive and receptive.
On this basis the Full Moon person has difficulty Focusing and can be indecisive. On a more positive level Full Moon types are seen as being more self aware and more objective than those born at a New Moon - they are a more rounded individual.
Much would also depend on which Houses the opposition lay in, as it would give some indication of the areas of life in which the opposition tended to manifest.
Traditionally Pisces is not a strong placement for the Sun, whereas the Moon may (depending on whether it is a day or night birth) have some strength in Virgo. All other things being equal (which they never are
) the Moon should be a little more dominant in your personality than the Sun.