People who insist on parking right next to you as you’re opening your door when the whole parking lot is empty: Why?

Probably because it’s the best parking space. Some people get stupidly competitive over that. Me, I personally don’t care where I park, and don’t mind walking. I knew a guy once though who parked, walked half way to the store, saw another car closer to the store leave, and walked all the way back to his vehicle to move it to that spot.