A star math lecturer’s diagnosis on South Korea’s persistently falling birth attributing part of the blame to Instagram overflowing with “flex posts” went viral Thursday.

In a video clip, uploaded to his YouTube channel, apparently from a lecture, Chung Seung-je shares his thought on the issue, starting with a question, “Koreans had more babies in the past when they were much poorer. Things have gotten a lot better now, but why do people have fewer babies?”

“Back when we were young, we didn’t know omakase dining and golf outings. Because we didn’t have Instagram,” he said, criticizing a social media trend in which people boast their success through lavish, conspicuous consumption.

Chung, then, told his pupils not to believe what they see on Instagram.

“These kinds of posts make you think that others are better off than you. It makes you feel like you are the only one unhappy or you are incapable of raising children the way others do.”

The remarks from Chung, who specializes in preparing students for the college entrance exam and is one of Korea's highest-earning lecturers, were echoed by many users online, especially young couples in their 20s and 30s.

One Twitter user, revealing that he or she has recently tied the knot, shared, “Whenever I see celebrities raise their children in a luxurious apartment with a view of the Han River and send them to expensive private English preschools, I become afraid of having babies because I think I won't be able to provide as much as others do for my child.”

Korea’s fertility rate dropped from 0.81 in 2021 to a new low of 0.78 last year, the lowest among member states of the Organization for Economic Cooperation and Development.

During a March public hearing, organized by the Ministry of Health and Welfare, participants in their 20s and 30s cited a culture of constantly comparing oneself with others as one of the reasons behind young people not wanting to start family and have babies.

Among other reasons cited for the nation’s chronic low birth rate were economic hardships, including housing issues, as well as the child care burden faced by dual-career couples.