Proof of how stupid I am

I was driven to near insanity by my frustration of failing to complete the final mission in "Grand Theft Auto IV." After skilfully guiding my Serbian serial killer through Liberty City's mean streets, I couldn't find a way inside an abandoned casino. I searched for hours, even climbing on top of the roof and peeking through little cracks in the ceiling, wondering if there was any way I could drop through. I searched everywhere, including adjacent buildings to see if there was some sort of basement entrance. The online walkthroughs didn't even address my problem. It just said "go into the casino." And then I looked again and saw there was this big-ass door in plain sight, right where it should have been. As you could imagine, I often have this problem in regular life.