Horrible advice. This may have been good advice 10 years ago, but not today. There are no positions for people who "kind of understand how toy LLMs work" because so many engineers do these days. Most of the real LLM optimization work is at the edge of research and highly proprietary and not something you could ever do without infra that costs millions. But of course, 10 years ago this wasn't obvious.
What would be better advice for a 17 year old?
What? You want me to tell kids not to be ambitious?