It makes perfect sense, but unfortunately I don't believe in luck or superstition. A load of phooey, I gone against every superstition in the book and nothing's changed from when I used to consciously avoid suchs acts, because I was young and foolish.
I once believed a certain band and their music brought me bad luck and have since discarded the CD in a field (Threw it like a frisbee, whooop!), my logic behind it was that when I first started listening to them things started to go wrong for me, people started falling out with me, found out my girlfriend was cheat, etc. Over time I stopped listening to them, and just forgot about them... until one day I found the CD under my bed and popped it in to have a listen, then things started going wrong yet again. Another breakup, falling grades, people treating me like shit, failure to get a job. I pinned my misfortune on the music. But since then, things have barely improved, like they did the last time I stopped listening to the music. Of course, I had my suspicions all the time, and knew it couldn't have been the music, at LEAST not completely but down to the fact that I'm a useless tosser.
This is why most people have bad luck, they make mistakes, they have up and down points in their lives, and if they happen to have a down point they like to blame it on a 'superstition' and think of something they've done recently which might account for their bad luck. In particular, this blame could take the form of a supserstition which could mundane, day-to-day activities such as walking under a ladder, having a black cat crossing your path, opening your umbrella up in-doors. ANYTHING at all to make them believe their misfortune isn't down to a fault of their own, but in fact something completely silly and unrelated to them in any way.
All of this is deep in the subconscious, of course and this IS just a theory so you know, don't jump down my throat about it. I'm in the same boat at you, I have no actual proof of this.
That's what I believe anyway, take it how you will.