A neutron walks into a bar and orders a drink. When it tries to pay, the barman says, “for you, no charge”
My informant first learned this joke during Orientation at USC the summer before her freshman year. She introduced herself as a biochemistry major and another student responded with this joke. The other student told the joke as an attempt to connect with my informant over the only personal information he knew about her. My informant warned me that the joke was silly before telling it to me, but the silliness of the joke was what allowed it to work as an effective icebreaker. The very familiar structure of the joke contributes to its cheesiness. At first, the audience is confused at the absurdity of a neutron walking into a bar. The “no charge” punchline, though, validates the “walks into a bar” setup. The joke plays off two denotations of the word “charge”: an electrical charge and a requested payment. The joke requires only a basic knowledge of chemistry (a neutron has a net electrical charge of zero), so the teller could be confident that my informant, as a declared biochem major, would understand the joke, and that they could then laugh about (or at) it together.