Final answer:
Dissimulate means to conceal or disguise one's true thoughts and feelings, which the protagonist had to do to avoid trouble in a restrictive regime.
Step-by-step explanation:
In the context provided, the word DISSIMULATE means to conceal or disguise one's thoughts, feelings, or character. When it is said that the protagonist had to dissimulate all of his thoughts and emotions, it implies that he needed to hide his true thoughts and feelings to avoid getting into trouble with a restrictive regime.
This action is often necessary in situations where there is a risk of persecution or negative consequences for one's true expressions, as indicated in the various historical and political contexts provided.