Honesty Is The Best Policy

If honesty is the best policy, why do we sometimes fail to tell the truth? Perhaps, though we recognise that candour can only bring the right result in the end, we worry about what may happen before we get to the end! We may fear that an admission will bring an undesirable reaction and we don't want to face the storm that then blows up, even if it is only temporary. A policy of buying time probably can be applied but like a dodgy, high interest rate loan, it will vastly increase the price that must eventually be paid. Is that price really worth it in the end?