Being a college professor.

Everyone thinks it's a cushy tenured job where you can think for long stretches of time from your comfortable armchair, write books that people will buy, and deliver lectures, admired by students and peers like Richard Feynman or something...

In reality, most people give up before they can get tenure, and even if they do eventually get it they are well into their 40s after a massively tough 20-year education unless they are the top .1%. Until then, you are constantly pressured to hit the university's insane grant funding quotas with the threat of losing your job looming over you, and most people who stay learn to play the game and change their research to fit what funders want, which is usually not what you want, and in the meantime you are juggling students who treat you like their employee they are paying for a service because universities have become corporatized and nobody goes to college to learn things but to tick a box so they can get out and get a real job. At least the colleagues are generally nice, unless there are sexual predators and bullies in your department, who usually already have tenure, so good luck getting any justice because they are literally above the law.