1. Never get involved in a land war in Asia.
2. Never go in against a Sicilian when death is on the line.
3. Headache with an abnormal neuro exam is always worrisome... and always look at there fundus.
4. Avoid diagnostic momentum - just because it sounds like gastroenteritis doesn't mean it is.
5. If a child has conjunctivits, always look at the ears and consider treatment should include oral antibiotics covering beta-lactam producers.