I was guilty of that very thing once. During my first programming class back in college, I wrote an Asteroids clone as a project. My professor kept sending it back telling me to fix it. I really racked my brain trying to figure out what he was sending back to me (he wouldn't tell me, I was supposed to find and correct the error). The game ran just fine. Finally a gave up and asked him to tell me the answer of what my code was doing wrong. He showed me that I had one line of code that was basically making a new instance of the entire game for every screen refresh. (I wrote it in Java, so Java was just correcting it for me in real time.)