Yes, I see exactly what you mean, and I do the same thing myself sometimes. I will read almost any book based on The Three Musketeers, for example, because I have read all Dumas ever had to say about those characters, but I am always hoping for another flash of that magic, another moment with those people, and sometimes I get it. The same with fanfic. And the characters in my head that are mine have their roots in some ways in the books I have read and loved -- they grew on the shoulders of those giants, they began in me trying to write something with that same kind of feel to it, that wonder that I had discovered in the books I loved most. Valdarrien is not d'Artagnan, but he owes something to him on some level: Gracielis began with me thinking through the Aramis situation -- what does it really mean to fail as a priest? I loved Swordspoint because it presented me with the same textures and flavours yet was something wholly new, wholly original. (I must own that I usually want to shake Felix, but I like Mildmay hugely and I adore Mehitabel.)
Lovely to meet you!