You should understand the code you write because it’s your job to do so. It’s like a car mechanic who understands the combustion engine and a doctor who understands the medicine he’s prescribing.

If you’re copying answers without understanding them, then you’re being a code monkey. The outcome is that code complexity, technical debt, and risk of bugs increase. As a professional, you have to set a bar on quality. Doing things blind will not help achieve that.

But does this mean you need to know every single detail? Not really. For instance, you can still drive without having a deep understanding of physics. But comprehending high-level physics will give you a better mental model of how a car functions.

So what is the conclusion? That learning is always part of the job. You won’t know everything at the start, which is fine. But you will gain greater knowledge each time you work on a particular problem. As your expertise grows, you will form more connections so you can dive even deeper.