You can try out some less-specific commands, like b, to verify that they don’t work with more and that you are indeed using more.
unset PAGER
If you don’t want to specify a pager anymore, you can unset the variable. man will then use more by default, just as it did before you set the variable.
echo $PAGER
Because PAGER has been unset, echo won’t print anything.
PS1=hello:
Just for fun, change your shell prompt. $ should now change; see Figure 6.2 for details.
export is not necessary, because you’re changing the shell’s own behavior. There’s no reason to export the variable into the environment for other programs to see. Technically, PS1 is a shell variable rather than an environment variable.
If you wanted to, you could export the shell variable, transforming it into an environment variable. If you do this, programs you run from the shell can see it.