Because I've seen how quickly people can learn the basics of how to punch
This is really a loaded statement. How does one define "how to punch?" There is a continuum of elements:
Making a fist and extending the arm with good elbow position.
Having a balanced posture.
Adding some hip for power.
Not being too tense, losing speed.
The above are minimal basic physical elements that lead to being able to execute a punch that
when landed will cause an effective result. Not too hard up to this point. Even an untrained seven-year-old can flail his arm and give you a bloody nose. So, in this respect,
one can learn how to do a basic punch in ten sessions.
One can learn to drive in ten lessons: Knowing how to start the car, put on the seat belt, how to tell the gas from the brake pedal and proper pressure to apply for smooth operation, how the steering wheel affects direction, etc. These skills will allow me to hopefully get from point A to B in many cases. But what about parallel parking into a tight space, judging needed braking distance, safely avoiding someone cutting you off or driving 65mph on the freeway? These skills will take more than ten lessons.
Throwing an effective punch
with a good chance of landing also takes more than ten lessons. Timing, closing distance, avoiding potential blocks, being able to minimize possible counters, tactics. It may take a year to be somewhat competent in these skills.
Not to mention having a mindset that lets you execute a punch at all under heavy pressure - this may take years.
The general concept of how to punch can be quickly learned, but safely landing it is another matter. Learning to punch is a progressive continuum of skills (physical, mental, spiritual). At which point does one label one's given position on this continuum basic, intermediate, advanced, expert?
Do you run self-defense courses, by any chance
It seems you and Gyakuto are using different deffinitions of "learning a punch." As this may be a subjective continuum, you can both be right!