Welcome to software development, where no one really knows what they are doing, the methodologies don't matter and everyone is wrong! Software is still a mix of art and science, there are a lot of ways to get to the right answer, and it is often very arbitrary and unbounded by physical processes. It might never settle, it might be like all the different methods authors use to write books -- strange rituals and personal patterns... there is no "right" way to author a novel -- might end up being the same with software. The end product is what you will be judged by...

> How do you teach people then?

You can't really, teach to the best of your ability and try to send students out with an ability to learn. It is MORE harmful to PRETEND you know what is going on than to openly admit you don't and are attempting to learn. False knowledge is worse than real confusion.

> Where can i learn how to do my job correctly?

In this field, it is a young and crazy field, maybe you will be the one who pioneers a way to actually do things more consistently... maybe you will just serve up another nonsense silver bullet.

> can you imagine medical students being taught "yea just try something and see what happens, hopefully your patient doesn't die and you'll learn something for the next patient."

Doctors kill patients all the time via mistakes, it is actually one of the leading causes of death in the western world... the half-life of medical knowledge tends to be less than a decade, so a decade out of school, a lot of what they know is wrong, or worse... actively harmful. We turn doctors into gods because it COMFORTS US, not because it has any connection to reality.