[sundarurfriend]

If you're not a programmer and are just stumbling around trying to code, ideas like DRY and abstractions and modularity are super useful. I work with scientists/PhD students helping with their code from time to time, and it's easy to forget how much basics we take for granted.

If you're a career programmer or want to be one, then yes, it's better to try things out and figure out from experience why these principles exist. Then, you can break the rules, because you understand their purpose and limitations now.