[wensley]

I started my first programming job at 28. Before that I did computer repairs and support. Starting that job was the first time I experienced still thinking about work, outside of work.

In a lot of jobs, your thoughts are free to wonder and you can think about whatever you feel like, whilst also working. Not so in software development, to do a good job your thoughts must only be about the task in hand and those thoughts can persist long after the task is over.

[jakupovic]

That's an interesting way of thinking of the problem. Personally I have been involved with manual and not so manual effort. Obviously digging a trench ends after you stop, but building an algorithm that does the equivalent thing, whatever that is, is not comparable as you don't stop thinking at 5PM?

[happy-go-lucky]

I can relate, and I guess the same holds true for any other knowledge work that requires such intense concentration.