When you have some experience trading, it becomes easier to pinpoint moments when you learned a lesson or had a major realization. You can see how your skills have changed and developed. You can even see how your trading style and attitude changes. I remember the trick that made trading click for me, and I thought, "Wow, I can finally make this work for me."
I understood how to stock trade. I went through the processes and learned all kinds of cool things. It didn't become simple until I figured out who I was. I realized was a greedy trader.
As I analyzed my plays, I began to see that I held on to plays for too long when they were going in my favor, and if they went against me, I actually did the same thing. I did that because I hated to lose, yet it was the exact thing causing me to lose. When I figured that out, I made changes that had a huge impact on my trading experience. Stock trading became simpler, and enjoyable.
If you're having trouble in your trading, or would like to learn how, and you want to know how to maintain focus, the most important thing is to learn about yourself first. Examine how stock trading makes you feel. Pay attention to the things that you do in your trades.
When a trade goes against you, learn from it. When you figure out what it is that you're doing wrong, and you figure out what your weakness is, you can work to improve that weakness. Use that experience to help you become a better stock trader.