Answer:
Have you ever thought that this might mean that you need to be true to yourself, like not trying to fake what you are?
But i believe it's a nice advice for modern world, as fake news, fake profiles and more are pretty common and it's hard to see if someone is trustful. For a great community there is a need of trusts and willing to be true, but if you see a community that enjoys hiding, then maybe this is a really wise advice.
If everyone was trustful, there wouldn't be any detective book.
Explanation:
If you're a person who believes in the sentence, it's easier to argue about it
