I think the lesson is that tech is a harsh industry to be in regardless of which tech you choose, and you should count on your skillset being obsolete in 3-5 ye

I think the lesson is that tech is a harsh industry to be in regardless of which tech you choose, and you should count on your skillset being obsolete in 3-5 years regardless. Also key is to not let what you're told to do at work decide what you're going to learn. Even if your current company is using whatever is the latest and hottest framework you need to be learning other languages, other ways of doing things. Here's an anecdote: I did some consulting work for an Indian-owned company in the US. I was helping out with some Rails stuff. It was a curious case of out-sourcing reversal. They had a hard time finding devs in India to do Rails because those developers felt that Java and EJB would be better for their resumes so that was the work they went for.