For example I want to learn more history or math. But as soon as I start reading or watching video, I start feeling sleepy. Rather than thinking “Oh may be I was not really interested in them” I’m curious to know your approaches to learning. If there is a better way to learn new stuff and keep at it.
The only suggestion I have is the obvious.
Only research a topic you are interested in. When it comes to history don’t feel the need to limit yourself to “traditional” history topics.
History of Film
History of Video Game developement
History of US skyscrapers are all totally valid historical pursuits.
That is one of the big reasons I give props to Erik Larson. He does a great. Job of telling unusual history and wrapping it around more engaging stories.