Ever been so self-assured that you made a ludicrous bet which you then went on to lose? I did exactly that about a year ago and it resulted in a mid-winter dip in Brighton.

Casablanca's on a Thursday night: me and my flatmate holed up in a corner knocking back £1 tequilas while I ferociously argued that Robin Hood did indeed exist.

Yes, there's a Sherwood Forest in Nottingham and yes, of course Robin Hood lived there with a band of merry men; stealing from the rich and giving to the poor. In fact there probably was a Maid Marian, niece to Richard the Lionheart, who Robin Hood saved from a forced marriage to the lecherous, power hungry, Sheriff of Nottingham. I think I was further excited by the Bryan Adams theme tune running through my head.

The argument reached a head and we rather giddily took to our bikes and raced home with the aim of settling matters on the student saviour and very reliable source that is Wikipedia. 

And it said:

Robin Hood is a figure in archetypal English folk tales, whose story originates from medieval times.

As I sat quietly considering the insulating value of lard, my flatmate set a time and date for my icy plunge and made sure a Facebook notification was posted.

The memory of this rather unfortunate bet emerged the other day when I heard a UKTV Gold survey being read out on BBC Radio 2. Apparently I'm not alone in my fictional naivety, and amongst the top ten fictional characters that the British public thinks are real include:

King Arthur - 65%
Sherlock Holmes - 58%
Robin Hood - 51%
The Three Musketeers - 17%
Lady Godiva - 12%
Robinson Crusoe - 5%

So I started asking around friends and family, putting this survey to the test. Bets aside, I found some surprising results. One of my mates (who requests anonymity) thought that Jack the Ripper was a fictional character and even worse, she admitted to believing Hercules had existed. Another friend admitted he believed that there was once a monstrous whale by the name of Moby Dick, and another confessed to thinking that Charles Dickens was a fictional character.

So, I'm interested to find out whether others have any similar confessions to share. Are my friends and I particularly gullible, or do we all have problems distinguishing reality from fiction?