when I say technical stuff I mean in your respective domains and software engineering in general.
So I don't try to learn every new thing in any depth. I just try to keep a bit of an eye on the overall landscape.
HN provides a lot of info about things that are going on, at a somewhat course level. That's enough for me - I don't need a fine-grained level for most things. When I see something that shows enough promise that I want to learn more, if there's not a link on HN, there's always Google.
At any given time I have three side projects going and I always wind up learning things certain things in great depth. For instance I have a long-running project of making decorative cards and it has meant getting extraordinary results with very ordinary equipment and had to write my own color management software so I know a huge amount about light and color and wide-gamut displays and such.
To be fair I did get a PhD which teaches you how to go out and discover the knowledge you need whether it is written down or not.
I very much like reading on a wide range of topics and have a vast curiosity that you will see in what I write on this site but when I really want to learn I start some project which is a little bit beyond the bounds of what most people are doing and overcome all the obstacles to getting there.