Right you are, Tony, he wasn't that old, and he wasn't in San Francisco, nor
Virginia or Carson City, where he apparently first used the MT handle on
February 3, 1863. (We could say Twain, the writer, was "born" in Carson on
that date)
Well, nobody said Star Trek scripts had to be historically accurate. The
"Print the Legend" rule is the norm in Hollywood, or in Time Travel science
fiction everywhere.