Grammar is fun if you have enough foundation. Just like building a house, without firm/strong foundation, it will not be safe to live. Everything starts from scratch.
It’s when you start to explore the world of grammar after grasping the very basic root. It’s also time to correct some mistakes you used to think to be right.
You know where you are; however, you still need to take further steps. the destination is clearer. It’s just that you are going to fetch it or not.
Academically, you are mature. Nonetheless, you still need to strengthen your existing grammatical knowledge.