Nothing in life is certain. Everything we believe is subjective. Evidence can be manipulated by predispositions and prejudices. Could you just be a brain in a lab being stimulated by electrical impulses? Or, if each cell in your body is replaced over time, maybe you are not even you anymore, like the Sugababes?

Sara Pascoe has starred in BBC's Twenty Twelve, Live At The Apollo, Channel 4's Stand Up For The Week, The Now Show, Dilemma, The Museum Of Curiosity and The News Quiz. Despite all this, she cannot be absolutely sure that she exists.

Join Sara and comedy pals Danielle Ward, David Reed and Rachel Parrish as she records her own BBC Radio 4 pilot, searching for the truth about monogamy.