The character lacks yearning–the “hole in the soul”
Every story is in some way a journey that moves the story’s hero from a place he is comfortable to one that is different from what he is accustomed. It is the trials and troubles that the hero deals with that allow him to see the hole and learn (and then know) how to fill it (and with what). The hero doesn’t know he has a “hole in the soul” until he’s forced to face it. Scrooge learns that he needs people (for more than money) as he is confronted with his past, present, and future. The hole in the soul is the hero’s blind spot.
Nullius in Verba 
I entirely agree with the need for yearning. Essential.
Does it matter if the character is aware of what he lacks from the start?
No. The hero rarely knows it. The hero generally doesn’t know he (or she) has a “hole in the soul” until forced to face it. “I’m doing just fine.” And often they are until the inciting incident upends their orderly world.
We don’t change unless forced.
This is my favourite so far. I can really relate to it.
“Does it matter if the character is aware of what he lacks from the start?”
Good question. I do not know. Usually the protagonist is in the denial phase, thinking “I’m getting by.” It’s the story that changes them along the journey.
Lesson learned. In The Baer Boys I now have Darin stating in the first chapter “Dammit all, I could really go for a beer. I mean, really. I yearn for a gosh darned beer. Or a nice cappuccino. Whichever.”
Or if he doesn’t know he has that hole it could, “No, I don’t need a beer. I just like the taste.”