[Ekaros]

Reference materials are very useful when you have problem and need solution. Books and articles do help lot in those cases. And being able or learning from the times you can't solve something and need support is what makes you an expert.

And then there is also keeping up with the current trends and best practises. You could be expert in some obsolete version of technology. And it could have been replaced in wide spread use with new version or different thing.

So some time spend on following podcasts or news articles or documentaries is useful, but I would say this is minor compared to actually doing the thing.