Does anyone else do this?

I keep thinking of writing my favorite authors and telling them how much I adore their work. But halfway through my mental draft, it always turns into a critique. "Oh I love your work so much, I reread your books often....original characters...interesting plots not found in other people's work....humor.....Oh, and by the way, can you stop using so much Deux Ex Machina? And when you're borrowing from an Earth culture for your fantasy culture, can you make it a little less obvious who you're stealing from? I think you're better than that."

This is why I never do end up writing fanmail.

I have actually done this in person when meeting an author too. (Open mouth, insert foot)