Hashem forgave the Jewish people at end of the second forty days, so what happened on Yom Kippur (the end of the third forty days)?

Concepts: Rosh Chodesh Elul and/versus Yom Kippur; levels of forgiveness; forgive and forget or forgive and not forget; can Yom Kippur forgive “all” sins?; repenting\forgiving from love or fear.

Also davening: Teshuvah Shleima (complete forgiveness); eating erev Yom Kippur; getting on wrong train, but then going in right direction.