Contributor/Getty Images
- Kim Jong Un turned 40 on Monday, according to the US.
- But he is skipping public festivities, with nothing scheduled or publicly announced.
- An expert said he may be forgoing a party because he doesn't think he's achieved enough for his age.
Kim Jong Un turned 40 on Monday, according to the US government's estimation of his birthday. However, he seems to be forgoing a big celebration.