Most of what is known about individual Vestals from the Julio-Claudian period survives only in passing, a name attached to an inscription with no surrounding narrative. Occia is an exception, and the reason is the unusual attention Tacitus gives to what happened after she died: rather than treating her replacement as routine business, he records that the emperor Tiberius personally took charge of selecting her successor, weighing candidates from two prominent families against each other in a manner detailed enough that modern historians of the Vestal order still cite the passage as one of the clearest surviving accounts of how a Vestal selection actually worked under the early Empire.
That level of imperial attention to filling a single religious vacancy says something about how seriously the office was still taken more than a generation into the Principate, when other traditional Republican priesthoods were increasingly hollowed out or absorbed into imperial ceremony. Tiberius, who was not a ruler known for personal warmth toward traditional religion, nonetheless treated the choice of Occia's replacement as a matter requiring his direct involvement rather than delegation to the pontifical college's ordinary procedure.
Tacitus's account gives Occia herself only a single, compressed sentence, the fifty-seven years and the unblemished purity, before the narrative moves on to the men contesting to place their daughters in her vacated seat. That imbalance is itself characteristic of how the ancient sources treat even a Vestal of Occia's unusual standing: the office earns detailed political attention at the moment of its transfer, while the woman who held it for nearly six decades is remembered in a phrase.