I have always believed that the real learning begins when one starts teaching. Everybody has their own reasons as to why they want to be a CFI. There are some retired Air Force and Airline pilots, who want to become CFIs so they can share their professional expertise with the new aviators. Most younger newly certified Commercial Pilots want to get their CFI so they can get their foot in the door, and start building those “magic hours” and meet the airline hiring minimums. And then there are some others who simply want to get their CFI as a source of self gratification and sense of professional development. There are other reasons as well.
However, no matter what your reason is, always remember, that the more “heart” you put into teaching others, the more you will learn yourself. The moment you stop improving yourself, as a flight instructor, you will stop getting better.
Here is a great article “So you want to be a CFI“. Click to download.