When I was younger, I knew how do simple things like checking the length of an array or joining a list of strings together or dividing two integers with various kinds of rounding/truncation. I could have told you instantly the correct syntax to do this in every language I knew.

Today, I probably couldn't tell you with bet-my-life-on-it confidence how to do those things in any language I know. There are a lot more languages, about half a dozen of which I currently use in professional work several times per week, but the five-second documentation search to check the right syntax* is completely auto-pilot behaviour now.

This was quite a disturbing realisation the first time I noticed it, but I've since concluded that with modern on-line help systems, general awareness of what tools will be available and what kinds of tricky issues to look out for is far more practically useful than being able to reliably recite specific details for specific contexts five seconds faster than a search would have told me.

*In the case of JavaScript, please allow five seconds for the initial search, followed by another thirty seconds checking sites like MDN or caniuse to see what is actually likely to happen in real browsers and whether some mundane functionality amazingly still needs a polyfill or other library-based alternative to work sufficiently portably. :-)