tldr: - In the 1940s, ~80% of kids were trained by their 1st birthday -By 2004, the average completion age was 37 months (over 3 years old) -That extra year

tldr: - In the 1940s, ~80% of kids were trained by their 1st birthday -By 2004, the average completion age was 37 months (over 3 years old) -That extra year of diapers = ~$3.1 billion annually for the industry -A pediatrician named Brazelton popularized "wait until they're ready" advice in the 60s — and later became a paid Pampers spokesperson, which is... a conflict of interest -Diaper companies responded by making bigger and bigger sizes (up to 65 lbs!)