In first year at uni, everyone was busy trying to make friends at our student union in the first week of term... I remember one night I was talking to this girl (who now is one of my awesome housemates and best friends) and I discovered that she was completely immune to sarcasm and was gullible enough to believe anything (she's now become extremely untrustworthy due to my teachings, however... and somewhat jaded... " )
By the end of the evening, she believed I was an 18 year old former, recovering alcoholic with a coke problem and with three kids to three different men :D