Who?

Who are you child,
who sits on my knee,
all dressed in purple and brown?
What is this riddle,
you just told to me,
about elephants, monkeys and clowns?
Your tale of visions
conjures, up in my mind,
a picture of events, yet to be
and reminds me of a day,
many, long years ago,
when it was I who sat on a knee.