What jokes do you have to know to understand?

Someone works in the operating room and is on duty on New Year's Eve. In order to "show the tireless style of medical staff to heal the wounded and rescue the dying", a TV interview team went deep into the operating room to shoot emergency surgery at night. The night nurse led them to change their clothes, briefly told them some aseptic precautions in the operating room, and then led them into a room where trauma surgery was being carried out. In order to choose the best angle to shoot the surgeon who is flying needles, the chubby cameraman slowly approaches the surgical instrument table with the camera, slowly approaching ~ The visiting nurse and the instrument nurse keep an eye on the cameraman, constantly reminding: be careful, be careful, don't get dirty, don't get dirty ... The cameraman responds: nothing, nothing, while continuing to approach slowly, slowly approaching ... Finally, the camera touches the instrument table! Nurse: Oh, dear! Dirty! The cameraman patted the machine with a simple and honest smile: nothing, just go back and wipe it!