The illiterate of the 21st century will not be those who cannot read and write, but those who cannot learn, unlearn, and relearn. --Alvin Toffler
Developers constantly learn, unlearn, and relearn. It's almost like the nature of our job. While it is totally fine to have 10+ years experience in some programming languages or database skills, the demand for new skills appear about every 2 year, if not more frequently.
Microservices, ReactJS, MongoDB, Golang, Terraform, etc. became mainstream a few years back. And you probably know some of the latest demand in Typescript, Rust, Svelte and Blockchain. We are tirelessly learning new languages, new patterns, new architectures, and new frameworks.
Almost everything that I do professionally is learned on the job. Not from school. There have been voices against university educations due to the ever-increasing cost and the slow to evolve curriculums.
But I learned "how to learn" in my college, which taught me how to "learn, unlearn, and relearn".
It was a big shift from the "stuffing the duck" education system I grew up with in Hong Kong. In many Asian countries, as many studies have shown, are prone to the passive "study for high exam scores" learning. That's why there are many countries have higher scores in international competitions than the United States.
I had a hard time adjusting in my college years, during when I was expected to learn on my own while also having a lot of freedom to choose my discipline. I barely graduated. But until much later I realized that what I learned is the methodology of learning, and how to put the knowledge to practical use. It gave me the tools for life-long learning.
Entrepreneurship is about learning, too. We learn, unlearn, and relearn what works and what doesn't. We have to figure out how to build a viable nascent product without any manual. The business model of yesterday gets refreshed with a disruptive newer model.