Being honest when lying would be easier is a private form of strength.

Telling the truth when a lie would be easier is often entirely unobserved. Nobody sees the moment, nobody could have checked, and there is no credit given. What you are left with is knowing you did it, and that private knowledge accumulates into something you can stand on later.

Watch for the small opportunities: an admission that would slightly embarrass you, a mistake you could plausibly leave unmentioned, a detail you are tempted to shade. Take one of them. The immediate cost is minor and the effect on how you regard yourself is out of proportion to it.