For the War Horse cast and colleagues, the week began with a celebration: a party to mark the first anniversary of the opening of the show at Lincoln Center Theater. For those who have been with the production since the beginning - among the actors, that number is 19 - the War Horse experience has been considerably longer. They began rehearsals in January, 2011, and one of the actors told me, "I can't believe it's been only a year, officially. I feel I've been in the trenches since August, 1914!" (If that comment had been a text message, it would have been followed with the obligatory "lol.")

Even those performers who weren't around for the hats and horns of a year ago tend to think of their War Horse experience as having had a kind of inaugural. I was reminded of this fact on Thursday of this week as I spent some hanging out backstage with Andy Murray, whose main role in the show has been Ted Narracott every since he gave his first performance on January 10 of this year. He has also gone on recently as Sergeant Thunder. 

Murray, who grew up 30 miles northwest of London and who moved to New York a year-and-a-half ago, after a two-decade stage career in the San Francisco, area, said that he remembers his first night onstage in War Horseeach time he discovers something new in his role. "Each time I have one of those moments - when I say to myself: oh, right, that's who this guy is - I want to erase all of my other performances and go back to my first night. As if my entire run might still be able to reflect that certain inflection or movement." 

Murray became an actor only in his early thirties, and said he has never had much official training other than "learn by doing." But he has a packed resume from places like California Shakespeare Theater, Berkeley Rep, and ACT. "I've done a lot of Shakespeare," Murray said, "and some of those roles have been demanding. But from a physical point of view I'd have to say thatWar Horse is one of the most strenuous experiences I've had. I basically hadn't been to a gym for twenty years, but I'm making up for lost time with this production." As he made this statement, he pointed to a yoga mat in his dressing room and began limbering up. 

"I'm very careful every night on the stage here," he continued. "You've really got to concentrate, and remain aware of your environment at all times. Behaving as if every night is your first performance is always a good idea, for many reasons." 

I suspect that his colleagues whose first War Horse night was a year prior to Murray's would tend to agree with him. 

Brendan Lemon is the American theater critic for the Financial Times and the editor of lemonwade.com.