To “always” remember one’s past sinful activities but avoid lamentation is one of the great challenges of Krsna consciousness philosophy. Srila Prabhupada expresses this very succinctly in the purport to text 27, Chapter 2, in the Sixth Canto, “Not only should one give up his past bad habits, but he must always regret his past sinful acts. This is the standard of pure devotion.”