Thermometers freak me out. It seems like 1 in about 3-4 brew session I freak out about them. It all started when I was a kid working at Arby's they would take all of them and toss them in the oven and trash the few that were way off. I couldn't imagine the temperature they read was so different.
I would be happy if could get 3 that read similarly!
Seems to me that calabrating your thermometer is better than freaking out or trashing them. All those you trashed as a kid could have been "fixed" with a cup of ice water and about 2 minutes of your time.
Batch 1 Brewing The American Revolution would never have happened with gun control.