The internet is filled with lots of information about different topics. I read a lot from Internet. It has ended up in such a way that I only read and do nothing with it. The problem is that, if the knowledge is not put to use, soon it will vanish from our head.
Above shown is a visualization which can help us to keep our knowledge updated. As seen in the image there are two ways where information flows in to us and two ways where information flows out from us. But the point here is that all these help to increase our knowledge.
Lets now dive into each parts
This is an input. As the name says, this part assumes that you have basic know-how of the topic. Most of the cases, this part is automatically satisfied. But in some cases it could be that you see a new topic and would like to understand more about it - For example in my case I was interested in machine learning and would like to know more. So I did some basic online courses like Coursera Machine Learning and also Practical Deep Learning for Coders part 1 and 2. Reading books on the subject matter can also help a lot.
This is also an input. There could be cases where you are so much interested in the topic and would like to get the latest news or trends in that domain. For this I think Twitter is the best place. I follow people who are having similar interest. There are also some websites and blogs which share such information.
This is an output but also an input indirectly. What ever you learn can be shared so that others would get helped. You can write a blog post or even share via twitter. I would highly recommend to write a blog so that when you share, you also might have to answer some questions yourself by which you learn more (this is why I said its an input inderectly). Other concepts of sharing are giving a talk in a forum. Maybe it could be in your local hackerspace or some conferences (in the past I did one in NIT). Another option could be to make a Youtube channel and share your ideas.
Putting your ideas into practical use is a good way to see if your understood the topic well. This would also help to get this topic stay in your head for long time. Try doing a small project (look in internet). For example see this Build an 8-bit computer from scratch - You can build your own CPU and there by gain more knowledge and indepth understanding.
It often happens that even though you put your knowledge into practice or share your knowledge, you still might forget things years later. Then you will have to go through the topics again. To avoid this, keep a notebook and jot down all the important points while learning. This notebook is your "second brain". You can refer important points (years)later with a small effort than reading the from the beginning again. Nowadays I use digital note taking - Microsoft OneNote on my iPad and Apple Pencil. If you have a writing tablet (like XP-Pen Star 06 Graphics Drawing Tablet), then you can use Xournal++.