Text:

This phrase “means it’s not complicated”. It’s used in sentences to reassure people or to tell people they’re being stupid in a nicer way. The tone is either calm or sarcastic, depending on the delivered intent. It was first heard from the informant’s father while explaining homework.

Analysis:

One of the hardest professions to have is a rocket scientist. The amount of schooling and intelligence required is considered unparalleled except possibly by neurosurgeons, where another variation of the phrase exists, “it’s not brain surgery”. The phrase is meant to convey that it is less than rocket science and, therefore, not that hard. It is used to soften or intensify a sentence, depending on the usage. Like most metaphors, it’s used to add flair to speech.