Taking accountability was just one of the many steps in life. Easier said than done, but people — many people — were living proof it was part of the way of life: happiness.
Nina, for one, would testify to the struggles of that reality.
Nina might not know her first life, but if she did, she would be thankful for all the pain. She would be thankful for everything that had happened because now, she had lived life for a while. It might not have been the fullest, but she was able to not just find herself, but create herself, which was the same thing.
Finn opened his heart and left it vulnerable just because he wanted to live — to experience life, to see the way of it. No meticulous planning or calculations, no backup plans, and no expectations.
Slater chose to stay quiet, keeping the greatest agony of life by bearing untold stories within him. He did so to live, to move forward, and to look his sister in the eye.