Why do people lie about their lives online?

I don't understand what they are trying to prove. All I do is school, gym and online. I like Yahoo! Answers, it's a stress reliever for me so I can honestly say right now, I don't "have a life". My friends are out of state and out of country so I talk to them on Skype and I do this. Anyway most of you are kids so there is not much you can do anyway. Maybe your folks won't let you go out. There is no point because sooner or later even online, people will find out that you're lying just ask Theffsrulz.