In my opinion, the market is very broad, dynamic and involves emotions, hence the reason it takes so much time to master.
Trading is not just about what you learn, but it is also about what you experience. Meaning, experience is also part of the refinement of the skills and knowledge you collect. That's what makes trading take time for you to master.
Every trader who starts at the same time, but with a different level of understanding and experience, will affect how quickly their trading develops.