Definitions by aichbea
OGB
Over grown baby. An adult who never really grew up. Also, someone who has the full mental and physical capacity of an adult but is more comfortable in the skin of their much younger self. Therefore, an OGB does not necessarily have a negative connotation to it at all, but is in fact a choice for being a playful person who eschews the idea that childishness cannot be part of the adult experience.
Problem child. Someone who thrives on conflict to such an extent where almost everything is perceived as a problem. The reference to the person as a child, even if an adult, is used in disdain as a reminder to the childishness of such a character.