food for thought

Is my grammar correct?

-In daily life, we have to play many different roles. In fact, we often put on different masks in front of different people. Before your parents, you have to pretend to be mild and orthodox; before your teachers, you have to put on the appearance of being attentive in class and being hard working at home; before your boyfriend, you have to show yourself a little ignorant and simple-minded lest he did not/does not gain a sense of triumph and superiority over his girlfriend; before your girlfriend, you contrive to display your erudition, though usually of a fake kind, to prove that you are well worth having as a boyfriend. Perhaps we need to run a campaign to urge people to return to their own nature and tear down their masks. Only in this way can we break down the walls between human beings, walls that are pulling people further and further from each other.