I remember what I learn more if it's relevant to work I'm actually doing.

So if, for example, I'm thinking about landing pages and I read some links on HN about building better landing pages then it gets lodged in my brain and I learn something worthwhile.

If on the other hand I'm just procrastinating I don't remember much or extract much value from being here.

One of the best uses I've found for HN is searching for past links related to what I'm working on; there's a lot of value in the old comment threads.