%attr_populator = {
     name => \_get_core_data,
     bday => \_get_core_data,
     sizes => \_get_clothing_sizes_data,
     grades => \_get_grade_data,
     complex => \_get_really_expensive_data,
};

sub AUTOLOAD {
  my $self=shift;
  my $attr=$AUTOLOAD;
  unless (exists $attr_populator{$attr}) die "Hey, that attribute does not exist!\n";
  &{$att_populator{$attr}}($self) unless (exists $self->{$attr})
  return $self->{$attr};
}