Start teaching that concept.

What do I mean By that, Well It means Start teaching others.
For example, Teach that concept to your younger brother. But, When you are teaching, You are going to hesitate, and not know that concept really clearly concept or how to define that concept. So, Then you are going to research for that. Like that you'll be master that concept.
Definitely, Not all people have their younger brothers.
So, I'll be going to show you 3 possible ways to do that:

• Start a YouTube channel. ✔️
• Start blogging on:
  • https://hashnode.com ✔️
  • https://medium.com ✔️

And there is a couple of websites you can blog on them. So, These websites were just an idea.

• Teach yourself in Mirror. ✔️

So, That's it.

I hope this will be helpful for you.