I'm doing a PhD right now. There are actually a LOT of external motivators: group meetings motivate you each week, posters and presentations motivate you each y

I'm doing a PhD right now. There are actually a LOT of external motivators: group meetings motivate you each week, posters and presentations motivate you each year, and publications motivate you the whole time. You also get some motivation from your peers and future career prospects. There's also the thesis proposal and defense. This all said, I ABSOLUTELY relate to you feeling "flat" or "complacent" or "content". You might feel like you have no inner fire, that you're just a Pavlov dog salivating at the world's treats. Here's three things I've kept in mind for myself: 1) Health is absolutely key (as others have already noted) 2) Keep your head above the water. I'm resorting to a cheesy self-help metaphor, but if you're constantly receiving external motivators, you're going to lose a sense of how you're feeling. 3) If you feel a spark to try something, but then lose that spark, maybe keep going for a bit. Everything has a learning curve, and the first steps are often more boring. But also I try to remember that productivity is not necessarily a virtue. You can always optimize yourself just a little bit more. Productivity obsession can just as easily be a symptom of my ego or my narcissism. I think this is a big part of self-help stuff. Marie Kondo doesn't just sell cleaning strategies, she sells PERSONAL TRANSFORMATION. Basically, make a couple changes if necessary, but I don't think you need to panic if you're not obsessed with personal accomplishment. That could be a good thing!