Age 30 is not a magical turning point, however. Openness declines gradually over many years, often beginning in the 20s. As the years wear on, novelty becomes less and less stimulating, and the world outside someone’s own private and professional sanctums becomes increasingly less attractive.

—Well, it’s good to know I’m no different than everyone else. Scratch that, it’s depressing. From the Scientific American article, Set in our ways: Why change is so hard