My existing baseball cap, very useful not only for keeping the sun/light out of my eyes generally but also for taking photos, was getting very tatty and I spotted the one above for €1 at a carboot sale in the grounds of the local Protestant church. I had been looking for a plain cap, but I figured the question mark logo was neutral enough, so I took it.
I've been wearing it for the last month or two and it was only yesterday that it was pointed out to me that it is from a Batman range of merchandising and represents the Riddler, Batman's intellectual enemy. Sure enough, on further inspection there was a Batman logo inside the rim.
How cool is that?