"誰もがかなりの期間、自分自身に一つの顔を、多数の人々に別の顔を見せ続けることはできず、最終的にはどちらが本当か混乱してしまう。"

Simplified Meaning:

If someone tries to act one way when they're alone and completely different around others, they'll eventually get confused about who they really are. Imagine a person who is very friendly and outgoing in public but feels shy and withdrawn when they're by themselves. Over time, this person might start to feel mixed up, not knowing if they are genuinely outgoing or shy, as their behavior changes depending on the situation. For example, if you always pretend to like something in front of your friends because they like it, but you don't actually enjoy it when you're alone, you might end up unsure about your true feelings. This can make life stressful and complicated. It's simpler and healthier to be yourself all the time, so you don't end up lost or confused about your own identity. By being consistent, both in public and private, you stay true to who you are and can build better, more genuine relationships with others.