Ask HN: What are the fundamentals for becoming a great engineer

I came across a blog post talking about the value of fundamentals in software dev (https://www.skorks.com/2010/04/on-the-value-of-fundamentals-in-software-development/).

What according to you would be the fundamentals to focus on to become a great software developer / engineer? As a follow up: what is a good plan to learn these fundamentals, assuming that university is already done with