[samvher]

You're right that it wouldn't be as easy for different kinds of jobs and working in a bar is a good example. Even there though, I think you could be clever about it - you can find opportunities that blend in with your work (e.g. coffee foam art, small talk in a language you're learning). These probably wouldn't increase your value as much but with some creativity I'm pretty sure in most jobs there is some kind of opportunity for learning.

[OneFamousGrouse]

> I'm pretty sure in most jobs there is some kind of opportunity for learning.

This is absolutely not the case.

[krageon]

There is a vast swathe of jobs that are labour under very strict conditions imposed on you by middle management, for example anything in a harbour or construction context. That's not the sort of rule that you can just opt to take some time for self improvement under. I would wager the percentage of jobs with such conditions is probably higher than without.