Letting the judgment of others keep you from doing something can make you miss out on something great.
These quotes show that letting the judgment of others deter you from something could make you miss out on something great. They do this by showing that if Park had continued to let other people's judgment of Eleanor keep him from talking to her they could never have had the kind of love they have now. It would have made them miss out on something great. Park even reflects back on what he first thought of Eleanor and thinks of how other's perceptions of her almost made him not talk to her. When he first holds her hand he worries about what others think and not just about he thinks that maybe he shouldn't have. But he realizes that he likes holding her and and he likes (even loves) her and he shouldn't listen to what other people think of her because if he does he won't have her.