The Miocene was the first epoch of the Neogene period (23-2.5 million years ago), followed by the much shorter Pliocene epoch (5-2.6 million years ago); both the Neogene and Miocene are themselves subdivisions of the Cenozoic Era (65 million years ago to the present). Climate and geography.
The dictionary meaning of the word Digress is 'to leave the main subject temporarily in speech or writing.' or simply deviate. As you say,I digress means  I am straying from the main subject right now. . Like in this sentence - 'I need to digress a bit to let the ink dry.'. Hope this helps :)
A digression is a stylistic device authors employ to create a temporary departure from the main subject of the narrative, to focus on apparently unrelated topics, explaining background details. However, after this temporary shift, authors return to the main topic at the end of the narrative. Examples of Digression in Literature Example #1: Iliad (By Homer) Homer is one of the earliest users of digression during the Grecian Era. He uses digressions in Iliad to provide the readers with a break from the main narrative, offering background information and enhancing verisimilitudes of the story.