I’ll intellectually/emotionally/physically hard as answers. For me its either 12 hours straight “punching tubes” on a very large scotch marine firetube boiler at the beginning of my career or Easter around a decade ago when I was working with troubled teens and had to engage in 5 separate protective holds in one 16 hour double shift. The former was all physical and the latter was a combination of emotional and physical.


I was about 3 months into my career as a software dev, and hated it. Hated the work, hated the company, hated the office. But I really had no other job experience and I knew I had to stick with it in order to get myself to a good financial situation eventually. In retrospect - the company could have been better about training me, but there wasnt really anything wrong with the job. But anyway, I coped with my impotent loathing by scrolling reddit for hours each day when I should have been working.
Which, at about 3 months in, led to a meeting with my boss where he told me that I needed to actually get shit done or I’d be fired.
So, appropriately motivated, I resolved to deliver the next project I worked on on time and under budget. I worked diligently on it for a few weeks, and then just before it was due to be demo’d, I found a critical bug in the software that required major architectural changes in the code. So for several days up to the deadline, I was showing up to the office at 9, working until 3 (am), going home to sleep a little, then back in the office - the whole time, of course, saying “fuck, I hate this. ihatethisihatethisihatethis IHATETHIS!”
The irony being that I had kept this kind of work/sleep schedule many times before doing physical activity or working on personal projects or playing video games, and felt perfectly fine. Tired, worn down… but fine.
The thing that makes hard work actually hard is that you don’t want to do it. When you have the tiniest ounce of giveashit, the work gets a whole lot easier.
Sounds like a nightmare, but also, that things are going better now. Good on ya for sticking it out.