When being covered in poop is par for the course. When T-shirts become your primary means of expression. When you've been used as a prop stand-in during game night.
You know you're Rob's kid when your crayon scribblings are in 72dpi.
You know you're Rob's kid when your math homework is filled with symbols in wheels.
You know you're Rob's kid when you find reading someone else's gamer drivel for hours at a stretch--followed by weeping openly for another hour over the inanity of it--to be an acceptable way to while away an afternoon.