No man has a good enough memory to be a successful liar.

A lie has to be maintained. Every version told to every person has to be held in mind and kept consistent, and the moment two of those people compare notes the whole structure goes. Honesty needs no bookkeeping, which is most of its practical advantage quite apart from anything moral. People who seem to get away with it are usually just early in the process.

If you are managing a story right now, notice how much attention it quietly takes. Consider telling the plain version to one person this week and feel how much lighter that corner becomes.