Marcus Aurelius was writing reminders, not building a personal brand

Meditations was written for Marcus Aurelius himself. The Stanford Encyclopedia of Philosophy describes a man repeatedly returning to problems such as mortality and irritation with other people, trying to put Stoic commitments into practice.

That changes how the repetitions read. They needn’t be evidence that he had effortlessly mastered life. They can be read as reminders of what he was still working on. A polished quotation gives you the conclusion; the repeated effort is often the more interesting part.