on the historical Jesus

Nick has reviewed Craig Keener’s The Historical Jesus of the Gospels, and while the review is fine, there is a section that annoys me.  It’s not Nick fault, he may not even realize it but it is something many a shcolar does and I’ll try to explain why it bothers me.  Here is the section:

The Jesus that we can know from our earliest and best sources (the Gospels) was an itinerant preacher/charismatic healer/exorcist/miracle worker who believed himself to have been commissioned by God to bring about Israel’s restoration.  He was an eschatological prophet who taught of a coming kingdom that he believed he would play a significant role in ushering in.  He envisioned his mission at least partly in messianic terms and called for radical discipleship, placing allegiance to him along the lines that were reserved for God alone, hence there is good reason to see continuity between the extremely early emphasis on Jesus’ exalted status and Jesus’ own exalted self-awareness (see esp. chap. 19).  In short, the historical Jesus of the Gospels is the Jesus that the Church has traditionally proclaimed.

I guess what bothers me is how the passive past tense is used as though Jesus didn’t really know who he was or what he was doing.  Did not Jesus know who he was and what he was doing from the time he was twelve years old, if not from before time began?   If so, why all the talk about “he believed himself to be…” “He thought he was…” so on and so forth? 

Thought?  Explainations?  Thanks.