Thanks to all who replied. Thanks to your instruction, it now is clear
to me that, in an infinite series of random characters, every
conceivable sequence MUST occur. These sequences must, of course, obey
the requirement that all random characters in an infinite sequence must
appear an equal number of times. This requirement rules out sequences
of only one character.
Therefore, in infinite time, the long-lived monkey at the durable
typewriter HAS to eventually write the works of Shakespeare, as well as
anything else conceivable.
More generally, everything that can happen MUST happen, not only once
but an infinite number of times.