They say that autologous costal cartilage calcification (it is not soft, so it is difficult and makes aesthetic mistakes when the doctor carves it) starts in the late 20s. Haha,
 I feel bad
 because I am going to have rhinoplasty so late since I am 30 years old.
 They say that even if you have autologous costal cartilage harvested in your late 20s, the quality is lower than that of younger people. Furthermore, as you get older, the
 amount of costal cartilage that can be harvested decreases, so get your rhinoplasty done quickly before you get old.
 For reference, this is the personal statement of Director H.O.J. Won at ㅇㅇㄹㅁ.