One of the things that occasionally happens to me is that
I mistakenly commit too much. I use Bazaar (bzr) as my version
control tool of choice, and tend to do "microcommits": every
time I make a change that is a useful, if very small, step in
its own right, and "make check" still passes, I commit, even if
it is only a one line change.

This means that usually all the changed files need to be
committed. Sometimes, but rarely, I make unrelated changes
in several files at the same time, and then I need to commit
each change separately. But then I forget to specify the files
on the command line.

With CVS, I would just shrug and continue. With Bazaar,
I do "bzr uncommit", which removes the latest commit from
the branch, and then re-commit with the proper files.

This is a small, but important, change from CVS, for me.
It makes me happy. "Ha! Foiled you again,
you stupid over-eager Enter key."

I have no idea whether other modern version control tools
have the same thing; this entry is not to advertize Bazaar,
but share my joy in victory over Enter.