But for me it was also a type of work where I put in some heavy work and got physically tired and slept well at night without a thought of the job. In my current project I'm in a leading position in some high profile projects and there will be high stakes decision that needs to be taken, there will be drama and opinions and you will need to learn a lot of things in a short time. Even if I would go home at a reasonable time I can still en up googling possible solutions to problems at work in the evening or thinking about how I should reply to an email.
That is mentally taxing in a different way and for me often as equally difficult to cope with as working in a tough physical job all day.