(something) is one thing, (something else) is (quite) another(redirected from is one thing)
(something) is one thing, (something else) is (quite) another
While it may be acceptable to do something, that does not make it acceptable to do something that is much more extreme or complicated than the first. Asking us to stay an extra hour each evening to finish a project is one thing, but demanding we work every weekend without overtime pay or else risk being fired is quite another. Expressing your affection for someone you've started dating is one thing; bombarding them with declarations of love after just a few days is another.