(Strip Number 1182, Original Publication Date, 25 July 1987)
Panel 1: The next day, we find Mike lamenting the fact that he does one dumb thing not worth worrying about and has to suffer two weeks. Given that he's talking to Brian instead of himself, he's lamenting being told he's grounded without actually being grounded.
Panel 2: He asks Brian if he ever wished that he could relive a day by erasing it all and starting over again. Brian says "Yeah."
Panel 3: He then says that if he and the others had that day to live over, they never would have spied on Molly in the first place.
Panel 4: Mike thought-bubbles that if HE had the day to live over, they wouldn't have gotten caught. This is baffling because there was no real consequence to his misbehaviour.
Summary: I would tend to blame Mike's sheer amorality on the inconsistent messages he gets from his parents. If no stable standard of right or wrong exists growing up, morality becomes a matter of avoiding detection, not avoiding bad actions.