Maybe he means that legally, pretending to be different people can be a potentially risky experience because when we interact with others as different people- like when you emailed someone from the disability services talking about what an asshole you were, and she responded as if you were that person- it can actually be a very big deal in terms of legal fraud, and it can be a generally violating thing to do to someone, to be dishonest with them in that way. I understand that you're trying to make sense of the world, but maybe the lawyer was trying to warn against impersonation as an effective way to make sense of things since it could harm you more down the road.