How to tell if you have more than one child...

The first child throws a tantrum at 19 months -- you pull out all of the parenting tips from the parenting handbooks -- "Sweetheart, I understand you're angry.  Can you use your words to tell Mommy what is wrong?  Mommy loves you even if you are making naughty choices right now" -- and so on.

Second child throws a tantrum at 19 months -- you roll your eyes and ignore him until he either stops or falls asleep.

Third child throws a tantrum at 19 months -- you take a picture because it's "cute."