He went to war because of her. Even after everything he still stayed by her. And she is like "you were the best choice, anyone should have been fine". Even with his son's marriage, he wants to prove that his marriage is not just political.
Usually, the time skip genre has MC turning back to the past with a total 180 personality change from the past self(like innocent FLs who gets shat on her whole life suddenly turn into scheming villainous after going back in time). Here I like how she stays with her dumb self even with her...