The original example was about how to approach keeping your house cool, 
not a manual on the innards of air conditioning. It said, for example, 
don't bother about the walls because the roof is more important.

On that basis my first rule would be:

1) Don't worry about any Ruby feature that you don't need to use. It's 
very, very powerful but unless you need to write something like Rails or 
you are an astrophysics PhD, then ignore all the fancy stuff.
-- 
Posted via http://www.ruby-forum.com/.