Heck, I find questions I have from old posts on CT all of the time. The embarrassing ones are the ones where I answered them 8 years ago but forgot. I think I collect in a pretty tiny sandbox. I am my own expert at times. Nothing beats the "Hong Kong" Continental Currency lady though. 15 pages on how "Hong Kong" stamped on a CC dollar DIDN'T prove it was a reproduction.
Trophy points, trophy points?...too bad they weren't badges, 'cause WE DON'T NEED NO STINKING BADGES!......
I become annoyed when a (new?) member posts coin after coin after coin asking the same question about each of them and not consulting the references offered so they can learn. The one question which seems to be asked most often is, "Is this a DDO?"
I've had this happen to me, too. Usually with posts dealing with Japanese coins or notes. People leave what looks like a desperate message such as "I need to know what this is!" so I, and often others, tell them and then they vanish never to be seen again. In a few cases I even did some research to find out what they had. My guess is that they do read the reply and see that their posted item has little or no value (a few were pachinko tokens, for example), so, disappointed, they don't bother following up. In any case, I've had far more people that do follow up with a "thank you" than those that don't, but perhaps I've been lucky.