Be an explorer not a parrot

To achieve karate greatness, you'll need to do more than just copy others.

It's only too easy in class to accept everything that your sensei says without question, or even without understanding. You do this kata or that move, and you learn to copy your sensei's moves to the millimetre without knowing the function of each twist of your wrists, each move of your feet, each turn of your body.

It's true that you can develop some karate technique by being nothing more than a mimic, mirroring your sensei's body like some kind of mindless parrot. In fact, when you're a beginner, you have to take everything on trust without any deep understanding for the function of the precise form that your imitate. But fairly quickly, you'll reach a stage where you'll need to know why you do something in order to do it truly effectively. You might throw a fist out quickly, just like your sensei, but if your arm is not relaxed on the way out, and your fist tensed at the point of impact, you're not doing it right, and you might even hurt yourself.

Why are punches better in long or short forwards stance instead of parallel stance? What's the real point of twisting your wrist at the end of a block? Why do you lift your knee to the side for a roundhouse kick instead of driving the knee forwards and rotating the leg at the end?

As you become more advanced, you should have more questions, not less. You may even question the wisdom of some of the things that we practice week after week. If you do, that's great. Don't so arrogant as to assume your interpretation is the only one, but don't be such a sheep that you follow everything blindly.

Martial arts have been developing for hundreds, if not thousands of years, and for most of that time, there was little scientific analysis applied to the styles. Even recently, it's been discovered that Europeans and Japanese should not perform many techniques in the same way thanks to physiological differences that make Westerners prone to long-term injuries due to their longer arm and leg bones.

The point is, there's plenty for you to explore, and you may even develop a deeper understanding of some things than your sensei. That's the way that knowledge evolves. A good teacher shares everything he knows, then the student uses that as the basis for further exploration and development.