One discovery often leads to another.
When you make a discovery A, you naturally wonder what you can use discovery A for, which can benefit many other areas of research.
Its like when you think of an argument for abortion after researching abortion, but you realize the same argument can also be used for euthanasia.
So researching arguments for one topic can lead to also discovering arguments which work for other topics too.
Same way, science and research works by learning something from one area and then realizing that you can apply it to other.
This is why its important to research all areas, because researching one area can help many other areas.
In simple terms, when one way doesnt work, try another.
But try many ways and you might even end up with best possible way which resulted from knowledge gained from trying many ways.
Its why its important to:
1. Learn about many different things and research many different things every day, moving from one area to another.
2. Write down everything, notice patterns.
3. Research what interests you.
Number 1 can be applied to any area of life. Take for example, gaming. You can play many different games during the day, which makes gaming more interesting, but also knowledge gained from one game could also work in another if you are playing some strategy games.
In chess, for example, its very good to try many different openings to learn what works for you, as well as learn from every game to apply that knowledge in next.
In usual thinking, for example, its good to think about many different things during the day. For example, you think about diet, politics, different social problems, morality, economy...
This makes your brain focus on many things, which increases brain's ability to do reasoning, since you are forcing your brain to think much more than it normally would, and it discovers much more than it normally would, thus it improves much more than it normally would.