This is a good question.
Short Answer: I say nothing
Long answer: You know I think there are friendly games without a clock, friendly games with a clock, and then there are tournament games. If we're talking tournament play, I say nothing for a couple of reasons. One, I think sportsmanship goes both ways; that is, both sides showing up to play and playing by the rules. So to me, if a guy forgets his clock, I have no more inclination to remind him of this than I would to offer him a "takeback" where he just blundered and lost his queen. I don't gloat over it but I win. Then #2, if I forgot my clock; we'll I forgot my clock! I lose; I might kick myself in the @@@ but I lose. To tell you the truth, in competition, whether it's chess, poker, darts, etc, I don't want to be on the receiving end of any "gimmies". I want us both to be bound by the same rules and you win or lose. I want to clearly win or clearly lose.
Like I said, good sportsmanship works both ways. Win or lose, I shake hands (or nod) and say "Thanks". Banjoman, I think it's kinda "ballsy" to go afterwards and ask the guy why he didn't remind you . IMHO
all games and sports have rules.mistakes cost so learn the hard way.i have and looked at my self not my oposition
Absolutely....
I also have this story:
Recently I played at the Marshall's, in NYC. The oppenent was right on top of my move. In other words, whenever I moved, before I could finish writing it down on the scoresheet, he would already make HIS move. At move 14 he didn't act. I looked at him, he started to put his hands in his face as if going into a deep thinking. I considered my move NOT special in any way. Something was up. It was. I forgot to hit the clock after move 14.
There are people like that all over, taking advantage not only the mistakes on chessboard but mistakes in procedures as well....
What can you do?