Most people within the Culture will spend a year or two as the alternative sex at some point in their lives, simply to see what it's like. The original Brahma was a lesbian whose start name was Madaleine; she chose to get transferred into a supremely masculine bodynote it is probably going that Zelazny didn't see the Unfortunate Implications on this time and again, but nonetheless had a nagging fear of not being man enough to draw ladies.