Actors often tell me that they have more offstage fun doing a serious movie or play or TV show than they do making a comedy. The reason is what you'd expect: when you spend so much time shedding tears, you need the release of constant laughter. I was not surprised, therefore, in the run-up to last night's spectacular opening of "Golden Boy," to notice that the level of jollity backstage was running especially high. Correction: the level of jollity in texts and emails was spiking, since like most 21st-century humans the "Golden Boy" actors, when not onstage, are more likely to communicate in the ether than in the flesh. 

Amidst the digital flurry, one communique stood out: an email from Dagmara Dominczyk, who plays Anna, to the "Golden Boy" company. It was headed: "19 Reasons Why We Are A Knockout." The 19 refers to the number of actors in the ensemble. The word "knockout" is fast becoming a reflexive term for this show: many of the rave reviews the production received resort to it, so much so that I'm thinking that it will have to be banished from the blog the way equine terminology is verboten for "War Horse." 

Anyway, Dominczyk's message was hilarious and high-spirited, though most of it was too inside-baseball -- and, even in our ridiculously transparent age, too private -- to cite in full on this blog. But number 11 is too good not to share: being in the show had inspired her to "want to write a knee play. A three-act knee play. About knees. Knees in the depression. Torn between art and commerce. Where some knees were 'scraping' by while other knees could afford great opulent knee-pads." Perhaps Dominczyk can collaborate on this project with Christopher Durang, or perhaps she, who has written a book called "The Lullaby of Polish Girls," coming out next June, should do it herself. In any scenario, I was touched not only by her massive list but by learning from it that every night after the show she catches a midnight bus at Port Authority to go back home to her kids in New Jersey: she doesn't get much sleep, since they want breakfast at 7 am. 

Few cast members, I suspect, got a lot of sleep after the joyous opening-night party, which was held down the block from the Belasco at the Millenium Hotel. I had spotted plenty of bold-face-name actors at the performance -- Victor Garber, Cherry Jones, Tyne Daly -- but the bash was dominated by the actors from "Golden Boy." How could it not have been? Nineteen is a big number -- positively a Times-Square-Sized crowd by the standards of straight plays on Broadway. I managed to chat for a moment for at the party with plenty of the ensemble -- Ned Eisenberg, Jonathan Hadary -- but I have to confess that I was a little remiss in my harvesting of remarks because I was seated during the post-performance meal with Ellen Adler. 

Adler is the only child of Stella Adler, renowned acting teacher and original part of the Group Theater, whose members were the creative ensemble of "Golden Boy" when it premiered at the Belasco 75 years ago. Ellen Adler was quite a young girl during the Group's 1930s heyday, but her memories of that time are vivid. She told me of summers spent upstate with them ("they worked endlessly on their acting technique, which was remarkably quiet by today's standards"), and taking the Queen Mary with the Group over to Britain, where "Golden Boy" was performed to great acclaim in London. ("My mother was so glamorous that people joked that 'the Queen had a queen onboard.'") 

Ellen Adler also told me about her uncle, Luther Adler, who played Joe Bonaparte in "Golden Boy"'s original Broadway production. I felt, however, that I wasn't the one who should be hearing this information. So I excused myself, trotted over to the other side of the party space, and plucked Seth Numrich, the Joe of the current production, from his throng of opening-night well-wishers, and guided him back, through a crowd of further fans, to the seat next to Ellen. Owing to the din of the festivities, I couldn't hear everything that these two said to each other about Joe and "Golden Boy" then and now. But I did wonder if Dominczyk, had she heard the discussion, might not have had to revise her list, making it "20 Reasons Why We Are A Knock-out." 

The new item would read: "Because History lives."

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