This debate brings to mind one of the more interesting differences between the hard sciences and other fields. This occurs when you firmly believe A, someone makes a compelling argument, and within a few seconds you firmly believe not-A, to the point of arguing for not-A with even more vigor that you used for A just a few seconds ago.

-- Lou Scheffer

(Most recent example from my own life that springs to mind: "It seems incredibly improbable that any Turing machine of size 100 could encode a complete solution to the halting problem for all Turing machines of size up to almost 100... oh. Nevermind.")