know (something) backwards and forwards
know (something) backwards and forwards
To be extremely familiar with a particular subject, field, or piece of writing, film, music, etc. I've read this book so many times, I know it backwards and forwards. You should ask Samantha about the issue—she knows car engines backwards and forwards.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
know something backwards and forwards and know something forwards and backwards
Fig. to know something very well; to know a passage of language so well that one could recite it backwards as well as forwards. Of course I've memorized my speech. I know it backwards and forwards.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.