Give thanks for that bit of insight. The different ideas that influenced Christianity need to be overstood:

1) the person of Jesus as a historical figure of Jewish cultural heritage(if he did indeed exist at all) - needs to be overstood in the context of Judaic beliefs as you have pointed out

2)the idea of virgin birth in the context of Roman and Hellenistic thought which was a product of Egyptian ideas.

Ideas were mixed and mashed with the result of a confusing story in the bible if one takes it literally.

THE VIRGIN BIRTH STORY

OTHER STORIES OF VIRGIN BIRTHS

It may be thought that the story of a virgin birth is too wonderful to have been invented merely to show that a misunderstood prophecy had been fulfilled, and that so miraculous a doctrine could not, without some basis of fact, suddenly be created by any brain, however fertile. But a study of ancient literature discloses the fact that myths of virgin births were part of many if not of all the surrounding pagan religions in the place where, and at the time when, Christianity arose.

"The gods have lived on earth in the likeness of men" was a common saying among ancient pagans, and supernatural events were believed in as explanations of the god's arrival upon earth in human guise.

About two thousand years before the Christian era Mut-em-ua, the virgin Queen of Egypt, was said to have given birth to the Pharaoh Amenkept (or Amenophis) III, who built the temple of Luxor, on the walls of which were represented:-

1. The Annunciation: the god Taht announcing to the virgin Queen that she is about to become a mother.

2. The Immaculate Conception: the god Kneph (the Holy Spirit) mystically impregnating the virgin by holding a cross, the symbol of life, to her mouth.

3. The Birth of the Man-god.

4. The Adoration of the newly born infant by gods and men, including three kings (or Magi ?), who are offering him gifts. In this sculpture the cross again appears as a symbol.

In another Egyptian temple, one dedicated to Hathor, at Denderah, one of the chambers was called "The Hall of the Child in his Cradle"; and in a painting which was once on the walls of that temple, and is now in Paris, we can see represented the Holy Virgin Mother with her Divine Child in her arms. The temple and the painting are undoubtedly pre-Christian.

Thus we find that long before the Christian era there were already pictured in pagan places of worship virgin mothers and their divine children, and that such pictures included scenes of an Annunciation, an Incarnation, and a Birth and Adoration, just as the Gospels written in the second century A.D. describe them, and that these events were in some way connected with the God Taht, who was identified by Gnostics with the Logos.

And, besides these myths about Mut-em-ua and Hathor, many other origins of a virgin birth story can be traced in Egypt.

Horus was said to be the parthenogenetic child of the Virgin Mother, Isis. In the catacombs of Rome black statues of this Egyptian divine Mother and Infant still survive from the early Christian worship of the Virgin and Child to which they were converted. In these the Virgin Mary is represented as a black regress, and often with the face veiled in the true Isis fashion. When Christianity absorbed the pagan myths and rites it adopted also the pagan statues, and renamed them as saints, or even as apostles.

Statues of the goddess Isis with the child Horus in her arms were common in Egypt, and were exported to all neighbouring and to many remote countries, where they are still to be found with new names attached to them-Christian in Europe, Buddhist in Turkestan, Taoist in China and Japan. Figures of the virgin Isis do duty as representations of Mary, of Hariti, of Kuan-Yin, of Kwannon, and of other virgin mothers of gods.

source: http://www.worldzone.net/family/johnanderson/indexd.shtml