It's difficult to know whether or not the ticket inspector has shot me a funny look on account of the golden crown I'm wearing, or because I've just set up a framed landscape of the Scottish Highlands on the table before me.
I decide to adhere to the Royal family tradition of 'never complain, never explain' as he checks my ticket, smiling in what I hope is a normal way, before taking a regal sip from my coronation souvenir paper cup.
Royal sources suggest that King Charles III enjoys a martini or a whiskey while travelling, but it's not quite 8 am, so I'm sticking with the soft drinks for now.
