Movie: A Distant Neighbourhood

I really liked this movie, however I was disappointed at not being able to figure out ... why did his father leave? Or should I ask... where did he go to? When the father was on the train, or just before he got on, he did not give much of a reason for leaving the way he did. We probably might understand his frustrations with ( married) life. There was even a song written decades ago... "Right or left at Oak Street... that's the choice we make every day"... so now I have to just use my imagination and try to guess why the dad left the way he did. Just asking. It's the only way I ever find things out.