Commentary on Meditations: B5:32

Why do unskilled and ignorant minds confound the skilful and the wise? Well, what is the mind of true skill and wisdom? It is the mind which knows the beginning and the end, and knows the Reason which informs all of existence and governs the Whole in appointed cycles through all eternity.

Hadot has an interesting take on this passage.  Marcus seeks to understand why unskilled, ignorant people confound the wise.  His answer: because the soul already "knows" (accepts Stoic doctrine) - almost alluding to the fact of a prior life that is savvy to ultimate purpose.

Full passage by Hadot:

Other themes also seem to be characteristic of Book V. For example, it contains two allusions to a Stoic cosmological doctrine which Marcus mentions very rarely: that of the eternal return. Usually, Marcus imagines the metamorphoses of things and the destiny of souls within the "period" of the world in which we are now living, without worrying about the eternal return of this period. This is what he does first, in V, 13, where he begins by affirming that each part of the universe, as it is born and dies, is transformed into another part of the universe. Yet he remarks:  

"There is nothing to prevent one from talking like this, even if the world is administered in accordance with determinate periods." 

In this case, he means, all the parts of the universe will be reabsorbed at the end of each period into the original Fire-Reason, before they are reborn from this same Fire in the following period. Elsewhere, in V, 32, we get a glimpse of the immensity of the space that opens up before the soul which "knows"-that is, which accepts Stoic doctrine:  

"It knows the beginning and the end, and the Reason which traverses universal substance, and which administers the All throughout eternity, in accordance with determinate periods." 

We do not find another allusion to the eternal return until XI, l, 3. 

(see Citadel p. 267