arrepentimiento

n. repentance, penitence, contrition

= regret, remorse, repentance.
Ex: Spalding's regret is quite understandable, for few of those seeking to identify particular editions in the catalog will fail to be confused by the results of this decision.
Ex: Moreover, significant gender differences are reported regarding remorse, depression, fear, anger, sadness, shyness, shame, surprise, contempt, concentration, astonishment, disdain, blame, & awe.
Ex: The book stands on the slippery ground between the picaresque and the Puritan repentance narratives such as the Pilgrim's Progress.
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* sin arrepentimiento = no-looking-back.