Twelve year old? Not exactly, but maybe sixteen or eighteen. I didn't get into computers before fourteen (well, didn't own one anyway).

• Tasks are often much harder to get right than they seem to. Roll your own for the sake of excercise and to delve into a subject for better understanding, but use modules when actually getting things done. Read the code of CPAN modules.

• Concern yourself with algorithmic efficiency. Don't microoptimize. Always keep in mind the information inherent in your data; there may be more than apparent at first sight. Though redundancy should usually be avoided as far as possible, a homeopathetic dose of it can work wonders so don't be afraid to make use of more memory where appropriate.

• Study Ruby or Smalltalk.

• Get a good understanding of what closures are and what they can be used for. Learn when it is appropriate to use dispatch tables, objects and closures, in any combination.

• Your strength is in abstraction. Concentrate on honing that skill, but remember laziness is important, too. Keep your hubris in check when you're trying to get things done.

Makeshifts last the longest.