Plenty is accomplished using such idiosyncrasies.
For example, most people, if asked by an authority "do you
understand these charges against you?" they would probably answer "yes". By stating such, they've just entered into a contract to be ruled by that authority.
The average person probably interprets that question to mean "do you know what you're being accused of?", when the authority actually means "do you agree/consent/contract to stand under to these charges this authority brings against you/do you consent to be a subject under my authority?"
The subject agrees, and can be "forcibly" drugged, or subject to any other punishment.