Those reasons which you don't want to reveal are pertinent
Without turning this into a dissertation, I'll try to briefly summarize. It's not that I don't
want to reveal anything. I'd like nothing better than for the world to sit transfixed as I endlessly pontificate about my opinions. That's about as likely as the possibility that the Jesus myths are based on actual instances of a man walking on water and levitating off into the sky never to be seen again.
There was
something at the core of the Jesus movement, this much is evident from the fact that it appeared so suddenly. I've heard theories that claim some ancient writers place Jesus in the Maccabean era, but I've never seen any direct support for this. I've even read that Philo of Alexandria wrote of a "Jesus" who was an archangel but haven't seen any direct evidence of this either although that would help sway my thinking that this movement was centered around a specific individual living during the time in question.
If there wasn't a specific person like this who formed the nucleus of this movement I would expect there to have been nuggets of its inception buried in the historical record over several centuries. The sect would have evolved slowly as philosophies and beliefs were borrowed from other cultures. It is
possible that christianity has its roots in the Essene sect (with baptism, communal living and asceticism being featured) but it's not a slam dunk. Either way it's still possible that the historical Jesus started off as an Essene.
We know that itinerant preachers were a dime a dozen during the time in question. John the Baptist would be an example. We know that occasionally an individual comes along with such charisma that he (or she) can become the nucleus of a cult very rapidly. In our own time we can consider such people as Marshall Applewhite, David Koresh and (maybe a bit earlier) Joseph Smith and Mohammad. These are common enough that to speculate that something like this formed the early core of this movement is a reasonable place to begin.
The presence of animosity between Jesus and the Jewish religious leaders is a constant theme in the canonical gospels. The cleansing of the temple narrative occurs in all four (although John puts it at the first part of the story). It makes sense to me that if this man did actually disrupt commerce by running amok, turning over tables, spilling inventory, etc., he would have hit some powerful people in the place they don't like to get hit: their wallets. It wouldn't be the first time a troublemaker like this got lynched and his body just disappeared.
The lack of a body in GMark is (to me) the smoking gun. In the older variants of that oldest canonical gospel Jesus never shows up after his death. But since his disciples don't know what happened to him they believe he will return. They begin "remembering" him telling them that he was going to go away and that he'd be back in triumph. It's just not a big stretch to go from there to angelic confirmations that he'd be back. As the original members of the cult began to die off or lose interest their stories could be substituted with stories of how they had actually seen Jesus after his disappearance. Eventually the death and resurrection scenario took form.
By this time Paul was involved in the cult. I have a feeling he made up some bogus story about how he had once been a devout Pharisee, persecuting Christians until he was forced to stop by a vision of Jesus himself (subverting his free will, incidentally). His revelations about what Jesus was telling him in visions quickly elevated him to rock star status in that community, and the rest is (revisionist) history.
The absence of any details of the life of Jesus in the authentic Pauline epistles supports not only his lack of knowledge of the individual, but also forms the bridge that gets us from the historical Jesus to the mythical one known today. Paul would have had tremendous incentive to avoid making up stories about things Jesus did or said in his lifetime because if one of Jesus's original disciples showed up and started challenging him on these things he'd easily be outed as a fraud. Paul's Jesus only spoke to Paul in visions and never talked about the past. Even so, Paul didn't quote Jesus in his visions; he commanded in his own words under Jesus's authority. Nobody would be able to accuse that "That doesn't sound like Jesus talking."
Because of this, over a couple of decades Paul's Jesus evolved into a figurehead, a tabula rasa upon which whatever story was desired could be written.
Paul's efforts at selling Jesus franchises resulted in small pockets of Christians scattered over a large area. As time went by there grew a need for more stories to entertain these people other than the god-man who sacrificed his life for them. So anecdotes about Jesus were fabricated. Stronger anecdotes became part of the tradition that eventually formed the framework upon which the authors of GMark wrote their narrative.
But (as now) Christianity was far from a cohesive group and as factions developed there came the need for other "gospels" that did a better job of supporting the particular beliefs of core groups in various areas. A flurry of gospels appeared, some very much like GMark, others quite different. The canonical gospels won the beauty contest. Others were eventually outlawed but many survived because people hid them away.
The presence of such inane miracles as turning water into wine serve no noble purpose, but they do demonstrate power over areas that were considered the domain of other popular god-myths of the day. This makes sense when the objective is to position one's favorite god-myth over top of everyone else's. Otherwise it makes no sense at all. Once one takes that principle into consideration it's not a difficult stretch to look at the various other miracles chronicled in the "life" of this character and more often than not see the correlation to some other pre-existent god's domain.
Again, I've tried to be brief but I can already tell I haven't.