Dan Carlin is an amateur historian and former radio talk show host. He now hosts two popular podcasts: "Common Sense" and "Hardcore History".Dan Carlin is an amateur historian and former radio talk show host. He now hosts two popular podcasts: "Common Sense" and "Hardcore History".Dan Carlin is an amateur historian and former radio talk show host. He now hosts two popular podcasts: "Common Sense" and "Hardcore History".