pacman -Syyu
Why two Y's? man pacman
was not very helpful in getting started either.
as far as i understand it:
-Sy looks, whether a new/upgraded package list is available. when it is, it downloads a new package list.
-Syy does not check, whether a new package list is available. it always downloads a new package list and overwrites the old one.
you only need -Syy e.g. after you have changed your from the stable branch to the testing branch of manjaro.
here are links to more detailed explanations of pacman:
http://wiki.manjaro.org/index.php?title=Pacman_Overviewhttp://wiki.manjaro.org/index.php?title=Pacman_Tips--------------------------------------
i do not recommend to explain to beginners how commands work. they just want to get something done quickly.
when people are interested how something works, they are not beginners anymore (at least not very long), because they start to read a lot about it and search for explanations. these explanations can be found in man pages, --help/-h options, wikis, forums, etc.