1. Your 3-year-old might get carsick on the way to airport while sitting in the back of a van that’s whipping along windy, bumpy roads and throw up all over herself and your feet while you're checking your baggage.
2. The ticket agent might forget to print out the boarding pass of the same 3-year-old and you may not realize this oversight until you’re next in line at security.
3. Your children’s Gaba (AKA grandma) may be looking particularly suspicious or maybe just the contents of her purse (think pad of paper and crayons for grandchildren, digital camera chock full of pictures of grandchildren, a wallet and photo sleeve with multiple pictures of grandchildren, etc.) raise security’s eyebrows and have to be thoroughly searched and x-rayed multiple times just to make sure that sneaky Gaba’s not hiding anything dangerous like a grenade.