So many things. All the baking and cooking subs for inspiration and advice, my country's sub for daily banter (made plenty of IRL friends through that) and all the subs dealing with people and relationships (relationship_advice) to see what people from all walks of life are struggling with.

Debian 9 running a webserver with Nextcloud, mostly. Also currently trying to get Matrix to work on a temporary Debian 11 device but we'll see how that goes.