Before law school, I researched a murder case in which the codefendants were still in prison, 20 years after the crime, and decided to help one of them, who identified herself as Jewish (though I later learned that only her father was halachically Jewish). This episode was part of the reason I became interested in law. When I told people the story in the past, some would be impressed, but others would opine that the convict should have remained in prison forever and that I was wrong to help her. I think it scared off one or two SDJ's, who might have questioned my judgment. (Maybe it makes more sense now that I'm a lawyer that I would have wanted to help someone in such a case, but it made less sense when I was doing so while an engineer.) So I stopped talking about the case and my involvement, and have since dated a few women for weeks without ever mentioning it. But I decided to tell the latest SDJ, and she was quite impressed. So it's probably a better idea to talk about oneself and risk disagreement, rather than never express an opinion in the hope of attracting a broader audience.
I think that sometimes shadchanim overreact to something they hear, so that suggestions or criticism from a shadchan may not necessarily be coming from the other party to the date. I.e., I tell shadchanim that several times girls decline to continue with me, with the matchmaker giving the reason that I was too quiet. Having heard that, the shadchanim may be overly sensitive to a girl's comment that I was quiet, or they may even ask the girl if I was quiet, and then tell me that I need to be more vocal and open. Thus, it may not necessarily be that a girl complained or was about to break up over my quiet character, but rather the shadchan may have overreacted.
And sometimes the single overreacts to the shadchan as well. The shadchan may be offering positive criticism, but it doesn't necessarily mean that the shidduch is going badly.
In any case, I may not be such a hollow shell at all, and I hope to continue with the latest SDJ.