It's also worth noting that "being famous" and "drawing crowds" in the ass-end of Galilee doesn't automatically make you an international rock star that will catch the attention of the Romans. It's notable that things go downhill (and quickly) after he arrives in a slightly more notable place, Jerusalem, which still is no Rome or Alexandria.
I don't think the idea that there was an apocalyptic preacher named Jesus going around around 25 AD or whatever was that much of a stretch, even if little of what's said about him after the fact is at all true.
The Chabad sect of Judaism has a not insubstantial number of members who believe that Menachem Mendel Schneerson was the Messiah. They believe that he performed miracles, and that he's going to be resurrected or that he never died in the first place. Some believe that he participates in their ceremonies in invisible form. This man died in the 1990s. If this conversion from a real person into a legendary being could happen in the Information Age, of course it could have happened 2000 years ago.
If you look at stories of say, George Washington and his "wooden teeth" or "chopping down the cherry tree," many US children learn about then believe for life one may get closer to understanding what happened to a historical figure. Then there are even ceiling paintings in DC that put Washington in the clouds in an almost divine-type pose. So you can easily follow how a historical figure accrued all this other stuff. We just have the benefit of more writing and reading than first century Judea.
Something a lot of people don't understand. When Dan matter-of-factly talks about "the traditions that were in circulation," this is pure speculation. There is no direct evidence whatsoever for a tradition, oral and/or written, developing around a historical figure. Q and the other "sources" the Gospel writers supposedly referred to are entirely hypothetical. They are just assumed to have existed. We don't have a scrap of this material, and more and more it's being demonstrated that the first Gospel, Mark (which the other 3 Gospels are all based on, including John) is structured on the Jewish scriptures and Greek literary conventions and techniques. It reads like a work of mythological fiction from beginning to end.