Only Question I ask myself: You are removing the first 2 columns of the first row but using the second column in all othe rows... Is that correct?

so here is my attempt notusing any module. As long as the data is not using quotes around the values it's, to my understanding, not necessary to use the modul.

#!/usr/bin/perl -w
use strict;

my $datafile = "stuff.csv";
my @fields;
my $data;

open DATA, "<$datafile" or die "Could not open $datafile:$!\n";
#I handle the first line outside the loop
# Throw away the first two fields (#, username) in the header
# Are you sure about "first two?"
(undef, undef, @fields) = split /\t/, <>;

my ($user, @userdata);
while (<DATA>) {
    chomp();

    # If you're sure about the 2 fields above,
    # I think we need to drop the second field here too

    ($user, undef, @userdata) = split /\t/;
    @{$data->{$user}}{@fields} = @userdata;
}
close DATA;
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