‘Before I begin…’ is an impossible prelude.
Common enough to call cliché, why at this instant have I revved up to ramble with that introductory preamble and tripped over my tongue, startled, by this covert – overt oxymoron?
The statement ‘before I begin’ becomes the beginning because of its sequence before the middle and end of a sequential/temporal set of topics. The informal and transitory nature of its position, acting as a bridge into an outlined series, allows a certain liminal leniency to the phrase.
Atypical and a-linear: before I begin begs the question if the equivalent of the phrase exists in other cultures that have a non-linear concept of time.