Multiple Handshakes

So, I was at a party and meeting lots of new people. You know how it goes. You introduce yourself and then shake hands. You might repeat the name several times because you didn't hear it because of the loud music or everyone was talking in the background. Then you promptly forget the name of the person you just met. Well, this happens to me sometimes, and sometimes I like to ask again, "What was your name again?" Usually, the person happily obliges, but what I don't get is that it is almost compulsory to redo the handshake. It's almost as if my hand pops out subconsciously for that second handshake as if it was going to make a difference in remembering the person's name this time. It didn't make one bit of difference the first time. Also, if I can manage to resist the temptation to do the handshake a second time, I often get the hand offering from the other person. He or she wants the reaffirmation as well, and you can't leave someone just hanging like that.