Milt, In what I've done which comes out of a so-called "traditional" background, e.g. Taekwondo, Hapkido, Judo, & Aikido (not so much the Muay Thai which I'll get to later), kata were/are important teaching tools. For us, when you are learning kata correctly, you are learning principles of movement (both singly and joined, as in when someone is "attached to you... some call it bunkai). A very simplistic, surface-level explanation is that it is the same as learning to write. The first thing you do is find out how to hold the writing instrument (i.e. how to stand), how to properly apply the utensil to the surface (i.e. how to move), then you are taught how to make the characters of the alphabet (i.e. the individual techniques that make up the kata), and once you are capable of writing a sentence in block letter form (i.e. able to perform simple kata with some precision) then you are introduced to cursive, flowing handwriting (i.e. introduced to some sort of free sparring exercise, in a mostly controlled setting). Keep in mind, in the typical educational environment, creative writing (i.e. really "doing your martial art") begins when the student has at least some nominal competence in cursive handwriting, because of its ability to ... flow. To me, that's why Kata exist. Well, on the surface, anyway. There are other reasons, which make themselves known to the practitioner after many lears of living with the kta, as it become an old friend who occasionally hands out new nuggets of good info.