Our Gemara on Amud Beis discusses why the cattle rustler who proceeds to slaughter or sell the animal, after he already stole it, incurs an additional penalty of 4 or 5 times the value of the sheep or ox respectively:

אָמַר רַבִּי עֲקִיבָא: מִפְּנֵי מָה אָמְרָה תּוֹרָה טָבַח וּמָכַר מְשַׁלֵּם אַרְבָּעָה וַחֲמִשָּׁה? מִפְּנֵי שֶׁנִּשְׁתָּרֵשׁ בַּחֵטְא. 

Rabbi Akiva said: For what reason did the Torah say that a thief who slaughtered or sold a stolen animal pays the fourfold or fivefold payment? It is because he has become entrenched in sin by slaughtering or selling the animal he stole.

What is this concept of becoming entrenched in sin?  It is not merely habituation. Imrei Dovid (Mishpatim 21:29) points out if this was habituation, we should require three times to establish this pattern, as with the ox who repeatedly gores (Shor Hamuad).  Imrei David says that a human is not an animal, and though has the capacity to function on autopilot, also evaluates and considers his past and future actions.  This is where intellect is both an asset and a liability.  An ox “learns” to gore, or demonstrates its propensity to gore, based on repetition (see Psychology of the Daf Bava Kama 24). However, a human, when he notices a sin, will either face the discomfort of his failings and repent. But, if he does not, when he cannot bear the pain of the cognitive dissonance, he will rationalize why it is permitted. That is why a person can become entrenched in bad behavior faster than an ox.

As the Gemara Yoma (87a) says, “Once a person commits a transgression and repeats it, it becomes as if permitted to him.”  Rav Yisrael Salanter was known to quip, “...And if he commits this sin a third time, it becomes a MITZVAH to him!”  Such is the power of rationalization.  However, rational thought also allows one to overcome a thoroughly entrenched habit, by deep reflection and honest assessment, as we saw in Psychology of the Daf Bava Kamma 58.