I wonder how many times in Unix’s history someone’s got confused/frustrated because nobody had told them about manual page sections and they typed `man crontab` and it had nothing at all to do with the file format (`man 5 crontab`).
Or the simultaneous relief and anger you feel when someone first explains to you that /bin/sh and /bin/bash are not at all the same thing, but on some systems /bin/sh invokes Bash, but it still behaves slightly differently to be more historically consistent and POSIX-fearing, but doesn’t actually turn off at least some of its non-POSIX features, etc, etc
Or the first time someone tells you that you don’t need to use `dd` to copy block devices, you can just use `cat`, `cp`, `pv` etc
That one sometimes makes people reel so much that you have to get them to try it out and do a checksum afterwards before they’ll believe you
Or the first time you try to print the string "-n" and you try `echo -n` and it doesn’t work and you try `echo -- -n` thinking you’re clever and it *still* doesn’t work and someone tells you about `printf` and how even the POSIX standard recommends not using `echo` but they can’t deprecate it because people just won’t stop
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko