Although Andrew had said these words casually, Ariza did not take them very casually. In this world, this was a golden teaching, even though it borders on common knowledge.
Daphne and Diana were also serious when listening to Andrew. Not only because he gave Ariza a piece of valuable advice, but because they understood that this was Andrew's philosophy and it was something to take into account.
They had formed a friendly relationship with Andrew, but that didn't mean they weren't careful with him. They knew that Andrew was anything but a normal character and as leaders of the country, they could not be so folkloric with these characters.
Although they operate under the idea of friendship, they are always careful when dealing with him and now that they have heard his philosophy they are secretly glad that they have not gone down the wrong path in their relationship with Andrew.