Distance
Let it be acknowledged that Hatake Kakashi was scared lf emotional bonds with others.
There were many things the man famed as 'The Copy Ninja' regretted. Many things which had caused him to distance himself from others. Many things that made him wish that he lived in a perfect world.
Hatake Kakashi's fear of closeness had begun as a child following the deaths of both his parents, and been cemented by the deaths of Uchiha Obito, Nohara Rin and his sensei Namikaze Minato. Following this Kakashi had established distance between himself and others, fearing that they would end up the same way his family, teammates and sensei had.
This distance had led to him failing several genin teams before finally passing one, partly because there was no way he could justify failing them, partly out of sentimentality. But even then Kakashi had not allowed himself to become close to his students. To become the parental figure that both Uzumaki Naruto and Uchiha Sasuke lacked or the mentor pushing Haruno Sakura to prove herself among her teammates. He had realise too late that the distance he created was doing more harm than good, and his efforts to avoid the fracturing of Team 7 had come too little and too late. Sasuke had turned to Orochimaru in search or power and vengeance. Naruto had left with Jiraiya to become strong enough to bring Sasuke back. Sakura had latched on to Tsunade, eventually becoming her student, to prove her worth.
The distance created by Hatake Kakashi, intended to protect both himself and other, ended up doing the greatest harm.
And that is what I meant by saying that we might be seeing more of Kakashi. One more to go, can you guess it's theme?