Four years seems like a very short time to reach early retirement. One presidential term. One Olympics.
In another, more real way, the way that involves me going into a job every weekday for nine straight hours, and stressing about work while I'm off the clock, four years is a pretty long time. It's too long to just gut it out: to put my head down and grit my teeth until we're financially independent. I need to find a way to actually make my career more fulfilling and enjoyable, so that these next four years aren't just a slog.