my $hi_mom = prefix_later(
   sub { my $f = shift(); print "got: $f\n"; },
   sub { print "this was unneccessary:\n"; }
);

$hi_mom->("nerp") for (1..3);
[download]

Output:

got: nerp
this was unneccessary:
got: nerp
this was unneccessary:
got: nerp
[download]