back to front
1
used to indicate one's complete knowledge or understanding of something
The origin of the phrase "back to front" is not precisely documented, but it is an idiom used to describe a deep and thorough understanding or knowledge of a subject. It suggests that someone is highly familiar with every aspect, detail, or component of that subject, as if they have explored it completely from one end to the other, much like knowing both the front and back of a book.
- The engineer understands the construction plans for this bridge back to front.
- Our tour guide knows the history of this city back to front; you can ask her anything.
- She's an expert in astrophysics and can explain the universe's mysteries back to front.
- After working in the industry for years, she understands the regulations back to front.
- Having grown up in the neighborhood, she knows the streets and alleys back to front.