You have too much to remember.
We all do; this isn't a unique experience to one individual.
A large segment of the population works as what's known as a knowledge worker: someone whose job it is to take in vast swaths of information and create something new from it.
How can you make this process easier? How do you hold onto more knowledge, to be able to work with it easier, to be able to associate various topics to find similarities and synergies between them?
A personal knowledgebase is a great way to help your process get smoother over time. A personal knowledgebase can go by many names, including a Second Brain, Zettelkasten, or wiki. Think of it as a place to keep any information you feel is or will be useful.
The ultimate question though: what do you feed into this knowledgebase?
Anything that resonates with you.
Is it interesting? Great. Jot down some notes and put it in. You now have a note that you can refer back to, add to, and leverage for future use. There is a balancing act between information hoarding and information gathering, and you will figure out the correct balance that works for you.
While several people do publish their personal knowledgebase online, there's no requirement for it. Keeping this private and personal is totally fine. It's up to you.
Over time, the size and quantity of notes you collect will grow. This is not a short-term project; this is a project for life. You can and should continue to contribute to your personal knowledgebase every time you find something that clicks with you.
You never know when that piece of information you saved will come in handy.