| mental overload
One thing that has helped me immensely with my memorization is by completely sub-merging my self into whatever it is that i'm trying to learn. To be specific, spending as much time as humanly possible going thru repetition after repetition until you are unable to rise to your feet again. Make it the first thing you think about when you wake in the morning and the last thing you think about before you go to sleep at night. Try taking a piece of paper and writing down every move of your kata over and over until the blisters on your hand finally bleed. This may appear bizarre at first but by doing this you are programing your brain to never forget whatever it happen's to be that your writing. This has worked for me on kata's and getting brutally efficient with various combination's | 
Effectively Learning Kata
Linear Mode
