Repetition is the Mother of Dogma
What Hoskote and Trojanow are trying to say with the statement that “Repetition is the Mother of Dogma” is that when something is repeatedly told to someone over and over again, they start believing in that something.
Let me take the example of religious beliefs to explain this better.
In India, a majority of Hindus do not indulge in eating beef. The reason they give for this is because cows are considered sacred and are prayed to. But nowhere has it been specified — not in the Geeta, nor in any texts. It is only due to the word of mouth that this is followed by many people. Since one person repeated the act, and told others, others believed it, and hence today, it has become a belief of the entire Hindu community.
Another way to look at “Repetition is the Mother of Dogma” is that Repetition is the best approach to learning. By repeating something over and over again, we tend to learn it and do it better and more efficiently over time.