If you begin, "Well met, Green, how goes it ?" as likely as not he replies, "Finely.

But I am no longer Green; I have become Brown.

I was adopted last month by my maternal grandfather." You of course apologize for your unfortunate mistake, carefully note his change of hue for a future occasion, and behold, on meeting him the next time you find he has turned Black.

Such a chameleon-like cognomen is very unsettling to your idea of his identity, and can hardly prove reassuring to his own.
The only persons who reap any benefit from the doubt are those, with us unhappy, individuals who possess the futile faculty of remembering faces without recalling their accompanying names.
Girls, as a rule, are not adopted, being valueless genealogically.

A niece or grandniece to whom one has taken a great fancy might of course be adopted there as elsewhere, but it would be distinctly out of the every-day run, as she could never be included in the household on strict business principles.
The practice of adopting is not confined to childless couples.