Nobody wants to deliberately use the wrong compression type when extracting, so modern tar will figure out the compression itself if you just point it at a file. So tar -xf filename works on almost anything. You don't need to remember which flag to use on a .tar.bz2 file and which one for a .tar.xz file.
It is "backwards" from some other commands --- usually you run copy/rsync/link from source to destination, but with tar the destination (tarball) is specified before the source (directory/files).
That, and the flags not needing dashes always just throws me for a loop.
And the icing on the cake is that I don't use tar for tarring that often, so I lose all muscle memory (untaring a tgz or tar.bz2 is frequent enough that I can usually get that right at least...).
I almost never create a tarball, so I have to look up the syntax for that. Which is as simple as man tar. But as far as extracting it almost couldn't be easier, tar xf <tarball> and call it a day. Or if you want to list the contents without extracting, tar tf <tarball>. Unless you're using an ancient version of tar, it will detect and handle whatever compression format you're using without you having to remember if you need z or J or whatever.
I got tired of looking up the options for each possible combination of archiving + compression, so today I have a "magic" bash function that can extract almost any format.
Then for compressing, I only use zip, which doesn't need any args other than the archive name and the thing you're compressing. It needs -r when recursing on dirs, but unlike "eXtract" and "Ze", that's a good mnemonic.
One reason is that tar supports both traditional style args "tar tf <filename.tar>" and unix-style args "tar -tf <filename.tar>" but there are subtle differences in how they work.
Literally the only time I’ve ever run into that is when I was trying to manipulate the path it extracted to. In 99% of cases I’m doing tf, xf, or cf plus flags for the compression type, etc, and those differences are irrelevant.
I used something recently where it wasn't possible to use the traditional-style args. I think it was a "diff", which meant I needed a "-f". It wasn't a big deal, but, occasionally it does happen.
I’m not saying it doesn’t happen. This thread started because I said I’ve never understood why people talk like tar is some indecipherable black magic. Common tasks are easy and there’s a man page for everything else.