I had this same anxiety when I clocked 30. Lol. While it is actually normal to feel this way, there are many new characteristics that come with being 30. You will just suddenly start exhibiting those traits, the funny thing is, you won’t even know about some of those traits until people start telling you. The first thing I realized about myself was that eating any kinds of meat suddenly started irritating me, I thought it was a moment thing until I found myself stop eating meat. Another thing I realized was visiting my folks, I grew so lazy to visit my family and friends. I found new hobbies, I started appreciating art works, I suddenly started traveling more to see new places. The traits are not fixed, it vary based on individuals. But trust me, 30 was a such fine age for me. You will love it.