I'm serious, there is always something to work on, learn or perfect in Karate. That is why we still "TRAIN" meaning still learning to do something properly.
I was once on a Karate course, kneeling down and watching the master demonstrate and explain a technique. Sitting down next to me, also listening and learning were; Kawasoe sensei, Naito Sensei and Shirai Sensei.
BTW the instructor on that particular course was Kase sensei.