How long did it take you to reach a high level of skill? I am a pretty good card counter but after playing around 100 tournaments I still make mistakes, sometimes stupid ones. It is very hard remembering the correct or almost correct play, not as mechanical at counting bj.
Don't get discouraged. I'm sure you're a much stronger player now than you were when you started. The fact is that decisions are often difficult, even with a lot of experience. While there have been certain times during my playing when I've had something of an epiphany about a particular strategy, the effect of experience tends to accumulate gradually. Don't expect to get to a place in your playing career where you think you have it all figured out. At least it hasn't happened for me yet.