From the article:
Walter White transformed from a mild-mannered, well-coiffed high school chemistry teacher into a terrifying, internationally-renowned bald drug lord in only five seasons.
Let’s also note that, while for many it was an excruciating, nail-biting five years of waiting for the new season (or, for the luckier among us, a few days of waiting for the next Netflix shipment to arrive) in the show that was one year.
I found Walt’s transformation mind-boggling even when I had no clue how quickly it was occurring.