• When you can drop the wheels on a target patch of ground no bigger than the length of the wing chord after an approach with the last segment in ground effect with the airspeed indicator not getting enough airflow to register.
• The dried cow manure under the wings covers a larger area than the oil stain under the fuselage.
• Small termite mounds in long grass are a taxi hazard.
• You know how to blow a nesting insect out of the pitot/static tube.
• A shower of rain in flight is seen as an opportunity to spruce up the aircraft and get it looking nice again.