She was used to taking things as they came, so she had no plans to change in the days after meeting him.
He was used to everything going according to his own arrangements, so he had already made arrangements before meeting her.
However, no one can predict the future. Even if they have arranged everything so clearly, none of them can go back to the past.
She sighed faintly, if life were just like the first time we met...
He smiled, if life could only be like the first time we met...