I hate to say it but the following are actually true for me...

You know you played too much GTA when you're out driving and you see a pedestrian on the curve and you almost jump the curve to run over them...

You know you play too much Persona 3 when you start referring to your friends as Social Links and talk to other Persona 3 fans about how your time spent together has raised your Social Link level...

You know you play too much MGS when you see a cardboard box and you have an urge to walk around in it...

This one is a variation of one someone else came up with but its too funny to ignore...

You know you've played too much of any game when you start to have "those dreams" bout your favorite character (you know the one where they're naked on a bed with silk sheet, and you have a bottle of massage oil... you know the one ) when suddenly, as the dream starts to get really good; your favorite character stops and says to you, "Don't you think this obsession with me has gone a little too far?"