Kakashi is the type of man that would ruin a relationship before he could even start. He 's the type to look at someone and think

I could be with you

only to toss that into the fire and move on with his life. He 's the type that would rather imagine loving only through the cold pages of a book written by a long dead man. He 's the type that would rather you hate him than love him. The type that would take a kunai rather than any kind of affection. The kind that would rather forget sentimentalities rather than indulge in it. The type that would rather you not remember his birthday or even celebrate it.

He 's the type that would rather spend time with the dead than the living.

Or at least, Kakashi was that type of man.