Conditioned Taste Aversion
Some people have lifelong taste aversions to food due to conditioned responses in their past. If someone has a terrible experience with a stomach illness near eating a specific food, that person can prefer to not eat that food in the future because they believe that food will lead to a negative response. This conditioned taste aversion can happen after one specific memorable episode, or can happen after several smaller, less memorable negative responses happen over time. These taste aversion stimuli can be outside or environmental factors that have nothing to do with the food itself. A person could ultimately spend their entire life avoiding a specific type or kind of food that is otherwise enjoyable to most of the population.