Four readers’ theories:
1) “According to Tom Burnham and The Dictionary of Misinformation, Fitzgerald spoke as a playwright. The second act of a play is where plot and character development takes place, spinning subplots and character reveals to give a play and its characters emotional weight and depth. The third act is meant to tie all of this together into a meaningful resolution. What Fitzgerald meant wasn’t that Americans don’t get second chances; he meant that Americans have no depth or development and tend to be rather two-dimensional, or worse. In fact, the remark is incredible snobbish — about what you’d expect from Fitzgerald.”
2) “I think it is often taken to mean there are no second chances, but I think that is wrong. What is a second act? In a two act play, the first act is all a building up and the second act is all dénouement. I tend to think he meant that in America, there is always opportunity and new beginnings, and none of the fatalistic inevitable failure of European thinking.”
3) “I’ve never assumed that it meant that there no second chances — I’ve seen
other people imply this, but always felt that this was wrong. The word ‘act’ indicates the second act of a play, thus he is saying that what would typically occur in the second act of a play does not occur in a typical American life. Note
that the second act of a play is not a second chance for all/one of the characters in it… it’s when things get complicated in interesting ways. I have thought (from the first moment I heard this quotation, and after all further thought) that his meaning was that Americans are born (get to know
their cast of characters), then die without anything of interest happening
to them in the meantime. Note that Fitzgerald had a number of expat years… his second act was in Europe. Scanning some Google hits, it seems that EVERYONE thinks that FSF meant ’second chances’. Don’t you think a writer would have said ’second chances’ if he’d meant that?”
4) “Don’t plays typically have three acts? I always thought that, given that, Fitzgerald was saying that American lives happen, comparatively, really fast.”