The real question is why we’re built to hate everything that’s good for us

Because we evolved in environments where the things that were “good for us” were either unavoidable or wastes of energy. We like potato chips because carbs, fat, and salt were scarce resources that our bodies needed to survive. On the other hand, running was a necessity for hunting, and running a marathon for no reason would be a pointless waste of prescious calories.

Similarly, writing is an exercise in delayed gratification. Few people write purely for the joy of writing - the underlying motivation for writing is that other people will read what you wrote and tell you it is good. Most writers probably had some formative experiences where their parents told them that the poem they wrote in 3rd grade was really good, and then some strangers on the internet told them they really enjoyed getting off to their space vampire slash fiction. But as a adult being judged by other adults, the bar is much higher, and so the time to write something “good” before recieving approval is higher, and there is much greater anxiety attached to the possibility of writing something “bad”. And your evolutionary drives don’t care about your identity as a writer - a monkey spending 3 hour scratching arcane lines in the sand without any other monkeys coming by to pick bugs out of their fur in appreciation should get bored and go look for berries instead.

I will also say that running for exercise, as it is normally practiced, is basically designed to make you fail at maintaining a regular exercise habit. You start off with this meme that running sucks and is awful, and even experienced runners will tell you it sucks to get started, or that they still hate running - so you’re kind of fucked before you even get started. Then you do what everyone tells you, waking up bleary-eyed at some fucked up hour to strap on your running shoes and run in the dark in your neighborhood, getting buzzed by similarly bleary-eyed blue collar workers in their rusted-out pickups, running until your lungs burn and you feel like you’re about to vomit, because that’s what everyone tells you running is supposed to feel like.

A far better strategy is to first assume that running will be enjoyable and pleasant from the start. So when will you do it? At 5am before sunrise every day? No, fuck that. Do it after work when you are actually awake. Or on the weekend when you are rested and have some free time. Running is fun. Weekends are for fun. So you can run on the weekends. And are you going to run in some shitty place where you are sucking in deisel fumes? No, fuck that - you’re gonna go to a nice park or a historic part of town or to the mountains or to the beach. Places where you aren’t worried about getting hit by a car and you can enjoy the beauty of your surroundings. And are you going to run and run and run as fast as you can until your lungs explode? No - you are going to go for a nice stroll, and then when the mood strikes you, you say “I wonder if I can get to the top of this hill as fast as I can” - and then whether you can or can’t, you tried really hard to complete a fun challenge. And to improve things further, you can just say fuck it to “running” and just join a pickup soccer club or something, at which point running will happen in the background while you focus on having fun and socializing with others, rather than staring blankly into space while you run for no reason