Characters Having Minds Of Their Own

Yet again my mind is being dominated by writing a story. The characters, though they have yet to be developed, are starting to have a mind of their own. Actions are not decided because I think it would be cool, but because the characters think it would be cool. The story is flowing, instead out of my mind to the page, like a river. Continually rushing, with no beginning and no foreseeable end. Don't you you love it when stories, plots, and characters are like that? As if they are writing the story themselves? I like to think of one Charles Schulz (the creator of the comic strip Peanuts) story. Although I can't remember the exact wording, Charles (or "Sparky") was having a conversion with a reporter about the lineup of the players on Charlie Brown's baseball team. It seemed there was often some discrepancy about which position each character would play, such as who was second base, because several players had been seen on it. Now I don't remember the exact words that Charles used to reply to the reporter, although I recall that it went something along the lines that he didn't know, they just picked positions themselves or something. Isn't that how writing is supposed to be like, letting the characters loose to wreck havoc on the world as we know it? Isn't more plausible that they are the one's in control, not us? Who are we that we think that we can tell them what to do? They have achieved sentience, and there is absolutely nothing we can do about it.