This is a pretty good example. Sure, we should know our tools, but This is not intuitive behavior if you don't know. https://superuser.com/questions/101676/is-

This is a pretty good example. Sure, we should know our tools, but This is not intuitive behavior if you don't know. https://superuser.com/questions/101676/is-there-some-difference-between-mv-and-cp-rm-the-old-file-on-unix https://superuser.com/questions/101676/is-there-some-differe... It is not until the last comment of the accepted answer that you get to the difference in permissions. (along with the answers that are not accepted as best)