Ask HN: First time in 4 years I lost interest working for startup. What do I do?

I have worked at the same startup for 4 years now. During a meeting last week I realized: I don't care about our product or it's mission anymore. I would rather be watching TV with my girlfriend or literally doing anything else.

I think I lost my faith. It's not burnout, I work 40hr weeks. But lately I just don't give a shit about bugs or features we're building.

What do I do? How do you deal with this?