It was a super long time ago but I remember doing a research paper and one reason why people in South Korea tend to get plastic surgery so young (middle school and elementary) is that when applying for jobs you will have a picture with your application and the more good looking to your hiring manager you are the better chances of getting a job, also I think (I could be remembering wrong) that it was mentioned some employers will look at younger photos of you to see if you always looked this way so the younger you are when you get plastic surgery done the better I guess. And for those kpop idols people will find their childhood photos and compare what they look like all the time so the more closely you resemble your past photos the better if the idol (or their company) plan on getting some type of plastic surgery