You won't grow as a person unless you leave your comfort zone.
If it makes you nervous, makes your stomach turn, and keeps you up at night, you have to try it at least once.
The more you're able to accomplish when you feel uncomfortable, the better you'll be the next time you attempt it.
Comfort comes by conquering enough times of discomfort.
Fear runs away when you face it head on.
If the goal is to be fearless, you better live outside of your comfort zone as often as you can.