"No one learns as much about a subject as one who is forced to teach it" - Peter Drucker.
When you learn something new, you may feel tempted to keep it to yourself. However, surprisingly- the most effective way to learn something is to share it!
Here's what happens when you teach what you learn:
So, create a study group, start a blog, make videos on it - try teaching whatever you truly want to master. As said by Albert Einstein, "If you can't explain it simply, you don't understand it well enough."