Honesty is the best policy.
Telling the truth is the most advantageous long-term strategy.
What They Mean
Lie less. The truth requires no maintenance, no continuity checks, and no memory of which version was told to whom.
Are They Right?
As policy, yes. The saying notably promises efficiency, not virtue or comfort. Honesty is recommended the way insurance is recommended.
What They Left Out
Some policies carry a high premium and are purchased only by the well insured.