No one really talks about this but line memorization (or the lack thereof) wreaks havoc in auditions, rehearsals and performances alike. The way in which you memorize can restrict your performance and that restricts your spontaneity and that’s not good. Another big problem happens when an actor thinks they’re off book but then when they go into performance the words don’t show up and everything comes to a screeching halt.
Make a study of how you memorize. Become aware of how long it takes you to memorize something and, more importantly, how long it takes you to be completely free of the book. Until the words just show up without you having to rummage around in your head, you are not completely memorized.
In the Green Room Professional Program the processes of memorization and script development receives a lot of attention because both have a profound impact on performance.