Stress

 
"Who's a good family? You are! Yes you are!" (Source)

If you're a nail biter who isn't confident about making decisions, air traffic controlling will be a highly stressful job. In addition to all of the responsibilities, air traffic controllers do not keep regular schedules. Shifts change all the time. Oftentimes, air traffic controllers find themselves working holidays. It's important to have a family (or dog, or whatever) who understands that you may work an erratic schedule.