I have an interest in technology. This place has a good offering of technology news and discussion that I can't find elsewhere.
Also, a significant number of my investment gains originated from stuff I read here (bought a bunch of Monero when it was $0.45/unit, for example).
Finally, I learned a little programming (mostly Go and C++) to automate some stuff at work and home (reports, backups, email notifications and things like that). HN is a reasonable litmus test for what people are using to do stuff like this.