To that end, the Feels will come to those witnessing or living through a particularly moving moment when their heart is fullest and add additional emotion until the heart can no longer contain the pressure.
Most parents start the training when their children are between two years and three years old. But there's no official age, and you needn't potty train your toddler at all if you don't want to.
There is a huge range when it comes to potty training. Some children learn as early as 15 months and refuse to wear (or need) diapers. Others are not potty trained until 2.5 or 3 years. Most continue to wear at least a pull-up (toddler diaper) until age 4 just in case there are accidents.