Just realise something:
The character would be based upon me, right?
Well, fridge brilliance on the part where my character falls asleep:
I find it difficult to concentrate on lecturers, so I'll just be in my own world.
So my character was sleepy and found it difficult to listen to the exposition related to the story, and was so tired he fell asleep.
That also explains why he might lose concentration to other exposition as well.
He also keeps to himself, and is maybe playful.
He's... also shy.
Which was a result of being used to being a loner.
Doesn't mean he's not friendly, nor is not caring.