No one knows everything about medicine, and often patients turn up before their symptoms get bad enough to match the descriptions in the textbook. It's only a matter of time before you miss something bad. If it hasn't happened to you, then you haven't seen enough patients. When it does happen to you, it will burn itself into your brain forever. It will eat at you and keep you awake at night, but the only way to keep going is to find a way to persevere and learn so you never miss it again. Accept the fact that you are going to miss something again and change your practice to reflect this fact.