The purpose of practicing kata is not to perform a solo routine, but to ingrain the movements in your mind and body, and to understand the applications. With much repetition and combined with partnered application drills, the techniques of kata become instinctual and effective for self-defence.
Kata can be practiced for aesthetic, meditative or exercise purposes and these are valid reasons to do kata, but they are not the ultimate goal.
If the entire sequence of a kata is challenging to remember, simply break it into smaller sections. The whole kata is never applied in a self-defence scenario. The kata simply offers options to apply depending on the situation. Understanding each short series of movements is more important than being able to perform the entire kata as a routine.
Think of kata as an encyclopedia of self-defence. Each individual kata is a book. Each short sequence within a kata is a chapter of that book. Focus on the meaning of the chapters and eventually you will understand the book. Over time you will collect more books and your encyclopedia will expand.
Enso Karate 