Explain SMBC — the wiki for Saturday Morning Breakfast Cereal

This comic humorously depicts how the experience of parenthood can shift a person's moral reasoning. The two panels show the same woman at two different stages: as a "Parent for One Day" and as a "Parent for One Week."

In the first panel, as a brand-new parent, she declares that hitting a child is despicable, motivated purely by moral conviction. In the second panel, after just one week of parenting, she repeats the same statement but now her reason has shifted from moral principle to fear of legal consequences: "They put you in jail for that, right?" The joke plays on the common parenting experience that even a short time dealing with the challenges of raising children can push a person from lofty moral idealism to the point where only the threat of imprisonment keeps them in check.