...that tomorrows tech is just a collection of encapsulated tech from yesterday.

So learn a couple modern web/mobile frameworks.

Their structure and workflow will show you current development trends and give you a taste of each piece before you take a deep dive.

For extra credit (and an enhancement to your adaptability), pick both a popular web stack and an obscure one.

Anecdotal: After being out of web development for 2 years, I spent last week with jquery/mongodb/backbone/handlebars/bootstrap and feel like I never missed a beat. I feel like I gained a beat! My last project before this was on a LAMP stack, so the transition was not only easy, but also refreshing.

Javascript is widely used for form validation. It is also more general-public facing than a compiler or any other infrastructure will ever be.

Blinking text? That was mildly funny nearly 20 years ago and didn't require javascript.

...is because diesel is less volatile, thus safer, should the vehicle come under fire.

Pi is constant.