Non, je ne regrette rien

Your average normal human being has roughly seven different options when it comes to a choice:

I have to
I ought to
I want to
I could
I'd rather not
I shouldn't
I can't

(We'll leave aside, for the moment, such irrational permutations as "I can't but I'll try anyway" and "I really should but dammit I don't wanna," which render our otherwise peaceable lives such an engaging mess.)

When you work in government - as a faceless bureaucrat, I mean, not a politician - most politicians aren't really in government anyway, they're in politics, which is a wholly unrelated field* - things are much simpler, because there are only two options:

I have to
I can't

Or "everything not forbidden is compulsory," as Wart's ants tell us in "The Once and Future King." T.H. White didn't work in government, but he attended post-Victorian English colleges - probably much the same thing.

The rule simplifies matters, but it's kind of a shame when there's something you feel you ought to do and you'd like to and you could but you don't have to so you can't. Coulda, woulda, shoulda just don't enter into it. But I suppose an aspiring career bureaucrat can't complain.

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*Watch a few episodes of "Yes, Minister" and you get the idea.