Excluding chasing the shiny object (the javascript race you mentioned) lifetime learning is part of the job description. If you don't love to learn and to apply the things you have learned the tech industry really isn't for you.
Also 1-2 languages... that's really on the shallow end most devs, myself included, will learn a lot more than that and each new language is much easier to pick up then the previous ones.
However as you get more experience, at least for me, you tend to stick to a handful of languages that each cover a domain.
OO, Functional, Dynamic/static variants and a language/stack that allows fast prototyping of ideas.
Also 1-2 languages... that's really on the shallow end most devs, myself included, will learn a lot more than that and each new language is much easier to pick up then the previous ones.
However as you get more experience, at least for me, you tend to stick to a handful of languages that each cover a domain.
OO, Functional, Dynamic/static variants and a language/stack that allows fast prototyping of ideas.