1. you are making a cake with a seven minute marshmallow frosting,
2. you have an almost three year old who is technically potty trained, but is still having issues getting to the toilet in time for no. 2
1. you will hear "I have to go! I have to go!" right when your syrup is at 240 degrees (2 degrees from when you need to pour it into the egg whites), and shortly before your egg whites are almost fully beaten, destroying both components, causing you to have to start again.