Very good points, Rumpelstiltskin. And in no way am I claiming that my observation is accurate. I was simply looking at this matter through the eyes of Freud. These defense mechanisms were proposed by Freud in the 1920s; although, a number of recent studies do suggest that many of us, indeed, use them. For example, denial and repression are among some those that are used quite often.
And by the way, both of your examples include senses - taste and smell. We are biologically preprogrammed, to some extent, to avoid certain foods (i.e., taste aversion to something that might upset our stomachs or poison us) and certain smells (e.g., a deadly gas of some sort). So that is also something to take into consideration.
There are also behavior psychologists (i.e., Skinner, Watson) who would attribute such aversions in terms of positive and negative reinforcement and conditioning. For example, let's say you love pizza. Then, one night you got extremely drunk, then had some pizza, then you vomited. Well, the next time you see a pizza, it might not look as appetizing to you because you've psychologically associated it with the experience of vomiting and being sick to your stomach.