Then I don't know about being an asshole or not, but I think your gf has a point, wouldn't you agree?
I think volunteering is a great idea because it'll help you meet new interestng people while you "work" a job that matters and helps a cause you believe in. Keeps your brain active, you build community, you get something new to talk about with your gf... so many benefits :)
Adding to what other people said there's volunteering for a cause you care about. It's a great way to meet other people that share your values.. be it helping with preparing meals for the unhoused, cleaning public spaces, planting trees, bothering your politicians, reading to elderly/kids/dogs, holding newborns without caretakers in hospitals, etc... look for your local organizations and reach out :)