@Victor Eremita,
Prove to me that you are not figments of my imagination. - Solipsist.
OK.. here it goes. i don't believe you can think of something or someone you have never met. you can think of the idea of a person and characteristics of a person.. even an imaginary person is made up of bits of all the people you know.. so it seems logical to me that i can't imagine these people unless i'm imagining them now after meeting them earlier... so i have at least met "you" that i am THINKING about.. not necessarily imagining.
it's the same reason we can't be in the matrix (stay with me).. if we were we would never have come into contact with the idea of it so we can't conceive it.. unless someone showed it to us before putting us in it.
in Robert M. Martins book - there are two errors in the the title of this book, (remarkably clever) he writes that we can't actually think about santa clause.. he does not exist and we have never met him as a result. you can think of the characteristics of santa or the guy at the mall in a suit or a picture on a soda can but you can't think about santa clause. (i am paraphrasing here but you get the point)
if the quote replaced "figment of my imagination" with "a memory" i feel it would be a more complex puzzle.