I have heard Dr. Andrew Ng point out the "well known" fact (in the computer vision community) that nobody, including Dr. David Lowe himself, really understands

I have heard Dr. Andrew Ng point out the "well known" fact (in the computer vision community) that nobody, including Dr. David Lowe himself, really understands why SIFT works either. So at least for those of us in the computer vision industry, this isn't maybe such a surprise.