actually the tap navigation drives me nuts, but the arrow/ok navigation is very different, it makes the memo you clicked ok about the "root" then shows associated links elow it. This kind of organization is not linear as you would normally think of it, which is why using it at first seems very "odd"
example
Linux(memo)
linkto Bash Commands(memo)
linkto sudo(memo)
linkto ntpdate(memo)
you could be reading say sudo, you want some examples, there is one using say ntpdate. But now you want to go back to bash commands to look up another command, the go up to linux for a directory structure of such-and -such
this is very efficient in navigation, think of it not in terms of outlines(this will mess you up) think of it in terms of internet navigation. Thats just my 1 1/2 cents.