It happens, but make sure that it is a conscious decision you’re making, not a reaction. Never quit when your pain and insecurity are at their peak. If you must retreat, quit when it’s easy, not when it’s hard. Control your thought process and get through the most difficult test first. That way, if you do bow out, you’ll know it wasn’t a reaction based on panic. Instead, you’ve made a conscious decision based on reason and had time to devise your plan B.