I completely agree with this. The problem is that to learn that quickly you generally need a dedicated mentor who is very skilled, and those people aren't usual

I completely agree with this. The problem is that to learn that quickly you generally need a dedicated mentor who is very skilled, and those people aren't usually readily available. I've thought about this in regards to SWE before. If I had an experienced SWE who was my dedicated mentor I'm sure I would improve extremely quickly. Unfortunately, that's just not tenable.