I've gotten similar reactions when discussing my current project. I box and my character boxes, so therefore, the character must be me? Or, in the very least, very similar to myself?
But that's not the truth. Do my character and I share a passion? Yes. Is the character (or any of them) based off myself?
Most definitely not. If the POV was the male character instead of the female, I wonder if anyone would even make that connection?
I do believe that some authors probably do create characters based on themselves, but I'm not going to make that judgement until I read multiple works from that single author.
That's one thing that makes me a loyal reader to a specific author. If I can pick up his/her different series, and have an entirely different character than from the last (though, sometimes there can still be similarities and that's okay), then it's a testament to that author's ability.
In this world of rampant social media, I think it's too easy to assume the author wrote him or herself in. You have an author who states something online, and then you see that in one of their books and the assumption is there. I think this can happen pretty easily with friends as well. When you know them BEFORE you read his/her book, it's sometimes easy to pick out your friend in the characters. But that doesn't mean the character is the author.
So, here I am, just stating that while many of my characters and I share passions, my characters are their own persona.