ibelk, I agree with you. I always try to keep silent when planning something great. Were there any situations when you really spoilt your plans by saying "Gop"?
Yes, there were situations where I failed after saying "gop", but it was long ago. Of course, I don't think I was jinxed. I failed then just because I lost concentration, and eased off too early, before the ultimate result of my actions was really achieved.
Since then I've always been following the wise saying about "gop". So now I usually fail after not saying "gop".