Body odor and childhood memories: emotional reflexes precede rational thought.
There are certain smells that cause immediate discomfort, even though we can't clearly name them. This reaction happens very quickly, almost instinctively, before our minds have time to analyze it. In many cases, the cause isn't the current body odor, but stems from childhood memories stored deep in the brain. The sense of smell is directly connected to the brain regions that process emotions and memories. As children, we associate smells with our circumstances: a hot kitchen, an old classroom, sick or stressful days. These experiences are "packaged" with smells, even though the smells themselves aren't bad.