I remember seeing a video of a rubber arm experiment that goes through a series of exercises to convince someone's mind that a rubber arm placed against their shoulder is theirs, while the real one is blocked out of sight. Once these phantom sensations are in place, the organizer then hits the rubber hand with a hammer, causing great shock in the subject but no real harm. The immediate panic is exaggerated by the fact their mind can't actually move "their" hand out of the way when they see the swing coming.

Another study had organizers shine a harmless light on participants' arm for a few minutes and see how they react, allegedly for some sampling purpose. The twist was that they would have the real subjects stay in a waiting room beforehand and watch actors leave while appearing to be in considerable pain from the session where the light was targeting. They then experienced a significant burning sensation from the "laser" despite the organizers insisting it was harmless. Some would go as far as to raise their voice and demand the experiment stop.

The idea is that people can be convinced that something is painful just from others' reactions to it. This may have been what the organizers were actually testing for, and the electrical shock wasn't real or was barely large enough to felt. But OP was just immune to being influenced. I would expect the ability to follow cues from others has strong correlation to success at socializing, so considering they use 4chan OP might actually just be built different.