I'm not op, but just spend an hour on wiki again.

For me it usually just happens randomly. Today it was because watching news which included the start of the last Ariane 5. I was mainly interested, how much "fuel" (propellant) is used and the relation between launch weight and payload weight. I quickly got distracted by rocket engines and read here and there.

Then I am currently reading a book about WW2 u boats, so I've read the Wikipedia regarding that specific type of U-boat, the torpedos, the torpedo calculation computer, the lives of several commanders, ...

Recently my kid played with clay, so I got to read a little about the process of firing clay, basically wanting to know if I can diy it.

Normally the things I want to know more about just fly in by themselves.