I think you should ask him. Say something along the lines of, "I saw the pictures of you dressed as a pirate at the bar on their Facebook page. Were you just back to visit?"
I don't know why he would lie to you about something so odd, but if it's bothering you, you need to ask before your mind starts going haywire and you start jumping to conclusions and then you're all worked up about nothing. (If you're anything like me...) Sometimes it's better to just calmly ask.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.