Lessons in Willpower

My consumer behavior professor said something the other week in class that made me think (and inspired me to write something for the first time in a while). She said, "You only have so much willpower. Once it's gone, it's gone. You can do things to build it up and build stamina, but you have a limited amount." She went on to talk about how you lose willpower every time you check your texts, refresh your email, etc. Which makes perfect sense. You only have so much energy to do everything every day, and when you spend ~5 hours on your phone and clicking refresh every 30 seconds, you no longer have that energy to do what you actually need to do. She also said something about research she found that people refresh their email ~750 times a day, which sounds crazy but I know when I am waiting on a certain email that I am constantly refreshing, so maybe that's not so crazy?