I would just like to add the comedy of knowing it's the persons very first day in the gym. They look so damn intimidated, looking at all the things they can do...
But theres nothing better than finishing a heavy ass set and sweat pours off of your face and stairing back into thier eyes because you know they have been watching you, and they look at you like " Son of a bitch that guy is a fucking animal".
Also it's not an ego thing, but it feels good to imagine theres no one else in the gym when your going hard. Example: When some dweeb is talking to his friend is in the way and you just barge through. Ok it's early I thought I had some better material... well I have a friend that works out his spinal erectors more than his biceps when he curls lol.