If I didn't get the solution..

Hi there, Nour El-din El-helw! You absolutely should not feel bad. Learning is a process. It doesn't just take time, but also effort. And what you've shown here is that you're willing to put in the effort which means that you will learn it.

Ironically, the best way to learn to solve problems is by solving problems. There will come a point where you see recurring problems that only vary slightly from ones you've solved before. It's basically a variation on a theme. But this is likely the first time ever even seeing this problem. It's natural that it will take you a bit longer the first time around. Have you ever seen a small child try and solve a jigsaw puzzle for the first time? Very often they just start trying to put pieces together a little randomly. But it doesn't take long at all until they figure out that the best way is to start with the edges first. Much like that, you will learn how to break down and solve problems through practice. As long as you're willing to practice, the possibility of learning and growing exists.

Also note that learning is not linear. Some things are just going to be a little more abstract and difficult to understand in the beginning. That's true for just about any topic imaginable. But once it makes sense, nothing can erase that. It probably did take you a bit to learn to add two numbers when you were small, but now it feels natural, doesn't it?

You might be interested in this blog article I wrote for Treehouse some time ago.

Anything worth doing and learning requires persistence and effort. If you're willing to give those, then the amount you learn is relatively unlimited.

Take a look at this quote by a fairly prolific writer and programmer:

"Every great developer you know got there by solving problems they were unqualified to solve until they actually did it." - Patrick McKenzie

A problem might not seem solvable on first glance, but somewhere there is a solution. Hope this helps!