It is not because the truth is too difficult to see that we make mistakes... we make mistakes because the easiest and most comfortable course for us is to seek insight where it accords with our emotions - especially selfish ones.
One must know oneself. If this does not serve to discover truth it at least serves as a rule of life and there is nothing better.
The heart has its reasons of which reason knows nothing.
Tell the truth work hard and come to dinner on time.