For brevity and clarity in the question: Using the __DATA__ label will enable folks to run this easily.
Update: Agh! the gotcha here is there are some lines with 2 key value pairs on em :(

#!/usr/bin/perl -w

use strict;
use Data::Dumper;

for(grep {/\w/}<DATA>){

    # g repeats the regex, e executes the Perl in the substitution,
    # returns the number of matches into the condition.

    # $1 and $2 are the bracketed matches in the regex in order.      
+  
    unless( s/^(^[a-z ]+) *: *([\w\d]+)/$_{$1}=$2/ige ){
        chomp;

        if (/:/){ # key part
            $_{$_}=join(',',@_); # make new key item
            @_=()
        }
        else { # list part
            push @_,$_
        }
    }
}
print Dumper(\%_);

__DATA__
Graq:
Agnostic:
Number: 634321
age: 27 hair colour: black
height: 73
weight: 123
legs: 2 arms: 2
jameson
bells
guinness
favourite:
detests:
likes:
[download]

--

Brother Frankus.

¤