Ask a beginner to write 100 words about a punch and the response may be, ‘what did I do wrong?’ It's cruel when all they can get is about 20 words. Ask the same thing, 6 months later, and you may get 200 words. A Black Belt might give you a thousand words and a Master Instructor will submit a thesis.
So a punch is not just a punch, an armbar is not just an armbar, in the anatomical sense. To a beginner a technique is just made of simple steps. To an experienced person, the technique is intricate with underlying steps and principles.
A BJJ student trying out Karate recently commented the training can get repetitive (this was only an observation comparative to his BJJ training). However, repetition is about deep understanding of the techniques and striving for perfection. Martial arts is not a theme park where you hop off one ride and get on another; it's the perserverance which will unfold the underlying steps and princicples of what you practice.
People often use the metaphor, ‘light at the end of the tunnel’ meaning to be patient because you're almost at the end of whatever it is you're trying to get to. In the martial arts sense that could also mean there is hope for every student because there is light at the end of the tunnel for everyone who perseveres. For most students the light at end of the tunnel is a Black Belt. A dedicated Black Belt will always seek another tunnel because it really is the journey, not the destination.