Situational. People are so unique that you can never really make one statement to completely generalize them. Except that one.
Even in cheating spouse situations, there are some people (my grandfather for instance) that had an affair because they were unhappy in their marriage. When faced with the choice to end it or work on it, they chose to work it out. It took them moving across the country and changing their lives completely, but they have a great relationship now.
Then there's my aunt, who is completely immature, and will cheat on anyone anytime anywhere over and over. She usually only attracts the type of guys who will put up with it for a long time and she's always in these long, drawn out relationships (been married like 6 times, 2x to the same guy)
Most people lie, if that's what you're referring to. I lie sometimes because I'm bored. Usually I'll just be messing with someone stupid, and if someone of marginal intelligence were to overhear, they would either rebuff, or laugh their heads off... depending on their sense of humor. Other than messing around, flattery, and situations where I may hurt someone, I'm brutally honest.
The answer is yes it CAN be regained. The question of whether it should be, is debatable and situational.