When I was a child - Judo for 3 years.......all forgotten.
Currently - Wushu (changchuan and associated weapons like broadsword, staff, rope dart, 9 section chain) for about 11 years and I still suck very badly. I learn one form, and I forget another.
In college - Wing Chun for 2 years....completely forgotten.
In college - Mixed martial arts (before it was known as mixed martial arts....our teacher just called it street fighting) for about 3 years...I used to be quite the thug, but now I'm old, decrepit, and completely out of practice.
Currently - Muso Jikiden Eishin Ryu iaido for about 2 years and still very much a beginner.
Currently - Omote Senke sado for almost a year....not really a martial art, but still an art.
My martial skills are completely crap, but it still interests me to study.