Great node ++. Some oft-repeated advice but it is great to have it all in one place, I can see this being a much linked to node and worthy of promotion to tutorials (it is currently under consideration for readmore tags).

On the topic of references I don't have The Perl Pocket Reference but I do have Perl in A Nutshell which lives permanently on my desk, I have long since given up trying to put it back on the shelf for exactly the reasons you describe.

You might be emotionally attached to a certain part of the code, so you do not change it.

A lot of writers fall into this same trap of emotional attachment "but I like this sentence/passage" and because they like it they can't see that it detracts from the piece of writing. The golden rule of editing is "be bloody ruthless", it seems like good advice for coding as well.