There are two options.
Or has faith in people, then gets disappointed or doesn't trust them in the beginning and gradually trusts them.
If we act in the first way, we turn out to be stupid, and if we act untrustworthy, in the eyes of those around us, we may seem awful, but, personally, we feel much better.
After many situations and many years of life in which I turned out to be stupid, now I choose to be untrustworthy.