I am glad western civilization invented internal guilt instead of external shame.
Lets say you board a train at an unmanned station with no ticket machine. Nobody checks your ticket. You then get out at a manned station, but can just walk off.
Do you buy a ticket? Many who don't will think "I don't need to", not "I just broke the law" or "I just committed a crime"
How about you instead also get off at an unmanned station. How many people will seek out a way to pay their fare?
You don't have to be a sociopath to not feel guilty.