Everyone has that colleague that can just "switch off" from work as soon as he leaves the office. It's like when they leave the office, they don't have any memory of where they work. I totally respect them. And not only because it's the right thing to do but because it's healthier. I feel the same way: for me, "I work for living and not live for work". I LOVE what I do, but if I had 10 million in a banking account, there's 34234 things I would like to do in my life other than work. Even in IT, I can think of 340 technical books I would like to read, 700 technologies I would like to learn just for fun and 890 systems I would have the time of my life implementing. Just simple things like an automation system for my home or smart traffic lights that know when an ambulance is nearby and switches the lights to give it priority. It would be fun! Nevertheless, I LOVE my work!
So, I can totally relate to my beloved coworkers that have the "switch". I don't have. I'm that guy that goes home thinking "why was that algorithm not working", "what can I do to improve the team's spirit" or "why didn't we do it the other way". Is it better or worse than the switch? It's just a different way of connecting to your work.
Vacation time is just a little different. I think about work anyway, but in a more scattered way. I do read e-mails every day. Crazy? Well, no. I know that my team can live without me with no problem. I know they won't bother me unless it's critical. But I read e-mails. I read e-mails because I have a team. Because even though I'm not physically near them, it's still my team. Their success is my success. Their happiness will make my life better. If there's an e-mail that they can answer, I'm not answering. But if there's an e-mail that I know if I answer I'll help them be more efficient (because I know something more about the topic or whatever), then I'm stepping in and dropping my "2 cents" to help them. And by team, it's not just the ones closer to me. It's the whole company.
So, is it better than the switch? Again, it's just another way to look at work. I would like to have the switch, but unfortunately I don't have. I do have a huge respect for the ones that have it.
Stress is not the problem: it's how you deal with it that makes the difference.