The return

He went to the jamboree in Sweden as a scout and returned as a sombrero wearing ukulele player. What happened?

Luke swapped one of his Irish scout t-shirts with a Mexican for the sombrero. In his own words "it was amazing" and lots of fun was had. However he does not want to go camping again for a while.

The ukulele was one of his birthday presents waiting for him on his return, it was his request.