No, there is proof that that's how it started. These "anecdotes" were passed down by narration initially, then they were recorded by two scholars: Al Bukhari and Muslim. The methods they used for verification were amazing, which is why we believe most of what they deemed valid. If you'd like to know more about how they did this, I can elaborate.

As for the Quran, it has been passed down by rote memorization. This is the difference between it and other books: people memorized it AND wrote it down. No other book in history has been memorized by so many people at once. Even now the record stands. Of course, the Quran could be falsely memorized in a localized instance, but not in all places at once. Many attempts were made to falsify the Quran systematically, but they failed due to the sheer number of people who had it committed to memory.

I simply don't agree with your opinion on belief.