IS THIS AMOUNT OF RETURN POSSIBLE?

[MoodSwing]

I have been thinking, and I need expert advice.
Let's imagine this scenario. The example will be long, but it is also realistic. Bear with me.

I have been learning for a long time (how long is unimportant), and I have 'perfected' just one strategy. I put that in quote because I know you can never be TOTALLY perfect, but the point is I see more profits than losses (like in a ratio of 4 profits to 2 losses. That's a steady 66% profitability).

I have a $1000 account, risking a constant 1% per trade. I am a day trader, taking 1-2 trades every day, about 10 trades weekly. My average risk-reward ratio is 1:1.5.
That means, in a week, calculating all those figures, I make about 6.6% of my account and about 26% monthly (And I'm not taking in consideration the compounding effect of 1% constant risk amount).

Now my question.
1. What is flawed in this idea? Because I see everywhere online, that ROI is impossible (26% monthly). Why is it not possible to have a scenario like this in real life?

Please be nice. I'm trying to learn.
Pardon the long example I gave, I had to make it clear. And if you want to know how I came to that 26% result, you can ask me to illustrate.