I would assume that, like most people, he divulges very little on a first date. It's where you try to put your best foot forward and impress the other person. You don't start to lift the mask until you're comfortable and think there might be some chemistry. I don't know how many dates he is getting through with any one woman before they decide to part ways, though his comedy routine would imply that it doesn't take long for that to happen.
What I'm trying to say is, his bad luck is probably based on poor first impressions. I would imagine a date with him was like that scene in the movie Beaches where the two women meet after years apart. The first women tells the other all about her life, then ends by saying "but enough about me! Let's talk about you! What do you think of me?"