A student at Sonoma College in the seventies carried around a cassette tape recorder and recorded everything. He switched cassettes every hour. Each was labeled with a date and a number, 1 through 24. Some days he had only ten tapes. If he stayed up all night, then he had twenty-four tapes. By the end of the week, his backpack was full of used cassettes. He never reused a cassette, so soon he had hundreds of them. The question is, if he ever listened to any of his tapes, did he record it?