I think that using marijuana excessively will make some folks feel lethargic and distant after a while. Others need it to get their "ideas", such as some of my artistic acquaintances whose life revolves around their marijuana habit. To be honest, they really bore me, as I know that all their energy and "performance" is fueled by their daily marijuana intake. I have a friend who is an actor and drama teacher and all his "bling" comes from smoking dope. Without it, he is strangely empty and flat.