Ego is a child of rationality. A rational person always wants to be certain. He is forever looking for proof but there is no ‘perfect’ proof. You may be convinced that a particular food is healthy but practically speaking, you can never know whether the healthy food you buy is actually healthy whether it is from a small village or a factory. Rationality is important but at the end of the day, you can never be 100 percent sure.
Similarly, ego is forever searching for the proof that it is worth something. You maybe a living legend, but your ego wants more and more proof.
In both cases, there is complete disregard for subjectivity. Everybody’s focus is on the food’s effect on the person and not vice versa.