Learning resources that finally helped you grasp a complex topic?

When talking with people about certain topics that are complex it can be easier to reference a blog post, video, or something else. For me, this is usually happens when I had difficulty grasping a certain concept until it was explained to me a certain way.

Here are a few resources that finally helped me grasp certain concepts:

- Javascript event loop: https://www.youtube.com/watch?v=8aGhZQkoFbQ

- Javascript closures: https://www.robinwieruch.de/javascript-closure/