Posted by EAH on August 26, 2003
In Reply to: Find out what the dog is all about - is it an idiom posted by Oleg on August 23, 2003
: Have you ever heard such a saying? Where did it come from?
It's a less formal way of saying "learn everything about the dog" and is generally coupled with "before acquiring one". The phrase stresses the word "all" ("everything").
A more generic phrase is "do your homework first".