In these modern times, the very concept of secret identities have been called in to question. Why have them? Would they even work? Are they ethical?
But most people forget the single most important reason for heroes to have a secret identity: a masochistic desire to have the woman you love insult you to your face, again and again and again:
The gentleman (who yes, is indeed a man) is Caius Martius Wheeler, a cop from ancient Rome granted limited flying power by the gods, who was put into suspended animation for 2200 years, and re-awoke in 1940 to fight crime as The Dart.
His secret identity is a teacher of ancient Roman history, and the lady of his desire is fellow teacher Miss Tilbury. Yet she never, ever passes up an opportunity to tell both the Dart and Caius how little she thinks of the teacher:
Maybe he just likes the abuse?
From Weird Comics #9-13 (1940-1941)