When I first started learning about Agile Methodologies back in 1999 (called XP then), I wondered why people needed to read books and take classes on the subject. It felt so natural to me that I assumed that everybody did software that way. However, when I entered the workforce in 2000 and joined a big company, I realized that it certainly wasn't the case.
There is a reason some of the best software comes from the open-source movement and small companies. Google's best product, Google Search, was released when the company only had two people. Now with thousands of employees, their new products haven't been able to match the quality and usefulness of the search product. Smaller companies are more accepting of "radical" processes like Agile, and is probably a reason they deliver higher quality software.
Agile principles aren't only for software development. They can be used in virtually every aspect of life. Have a huge stack of mail to go through at home?
Iteration 1: Make categories for your mail and sort them.
Iteration 2: Process category 1
Iteration 3: Process category n
Need to clean the house? Do a little bit in each room as you use it. Happen to be in the living room? Dust off the TV. This is like continuous refactoring. You shouldn't have to schedule time to refactor, because it will never happen as higher priority issues take precedence. You should be refactoring and improving your code all the time.