I repeat things, because repeating things is a good idea. From "The impact of repetition-induced familiarity on agreement with weak and strong arguments":
Repeated statements are perceived as more valid than novel ones, termed the illusion of truth effect, presumably because repetition imbues the statement with familiarity.
In 3 studies, the authors examined the conditions under which and the processes by which familiarity signals from repetition and argument quality signals from processing of message content influenced agreement with persuasive arguments. Participants with low or high motivation to process information were presented persuasive arguments seen once or twice. In all 3 studies, repetition increased the persuasiveness of weak and strong arguments when little processing of message content occurred.
Two of the studies used a process dissociation procedure to reveal that both greater controlled processing (which reflected argument content) and the greater automatic influence of familiarity (which reflected repetition) were associated with increased acceptance of strong arguments but that greater controlled processing dissipated the benefits of familiarity for agreement with weak arguments.
Go forth and repeat thyself. As if often the case, people will say, "No, duh." Everyone knows that you're supported to, "Tell them what you're going to tell them. Tell them. Tell them what you told them." And, "Even a lie repeated often enough is seen as truth!"
If we audited your briefs and opening statements or oral arguments or opening statements or closing arguments; would see a pattern of reptition? Do you repeat yourself? As is often the case, abstract instructions like, "Repeat yourself," get lost in the concrete world of written and spoken work.